From patchwork Tue Nov 12 00:06:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238311 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0459814E5 for ; Tue, 12 Nov 2019 00:10:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCFF621872 for ; Tue, 12 Nov 2019 00:10:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="XgxPYsGD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727665AbfKLAKW (ORCPT ); Mon, 11 Nov 2019 19:10:22 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10648 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727321AbfKLAHR (ORCPT ); Mon, 11 Nov 2019 19:07:17 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:07 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:05 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:05 -0800 Received: from HQMAIL107.nvidia.com (172.20.187.13) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:04 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:03 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:03 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard , "Kirill A . Shutemov" Subject: [PATCH v3 01/23] mm/gup: pass flags arg to __gup_device_* functions Date: Mon, 11 Nov 2019 16:06:38 -0800 Message-ID: <20191112000700.3455038-2-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517228; bh=/JjGbVZJ8qaDHiJyVc8rKJC41LC1ZjvKm126SlEIWtY=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=XgxPYsGD5Cq3FBIJISLcRetCEazTGocWyf543MWJh0xxa/0V54dx42FHTdiMbtp9G bkhWUIOYRWPTqeAghnzLlcKq+4jG/ziNrBs8to4cFX5tjldntCGFxly2FDb/7dtuPB ofXOYWSWPiPo4pLPCp6sVUzJBklCoqa+pD5cMreZdifwGntgrWsOQZZezVmEDqPJnr WyAc41nboTdDAQA1l/f+ButLI0Guqa0dZMyR8Qo6jQgFrGI5VdU/2VYWZ9h0Rt7eWK V/9Hp3cxn3NKCsyExhyTjLc2HiWqAtDKfUPVARyab/T8fsXF3grzwRklGIWCTRClJw wkZJz9tcQbExw== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org A subsequent patch requires access to gup flags, so pass the flags argument through to the __gup_device_* functions. Also placate checkpatch.pl by shortening a nearby line. Reviewed-by: Jérôme Glisse Reviewed-by: Ira Weiny Cc: Kirill A. Shutemov Signed-off-by: John Hubbard --- mm/gup.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 8f236a335ae9..85caf76b3012 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1890,7 +1890,8 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, #if defined(CONFIG_ARCH_HAS_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE) static int __gup_device_huge(unsigned long pfn, unsigned long addr, - unsigned long end, struct page **pages, int *nr) + unsigned long end, unsigned int flags, + struct page **pages, int *nr) { int nr_start = *nr; struct dev_pagemap *pgmap = NULL; @@ -1916,13 +1917,14 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, } static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, - unsigned long end, struct page **pages, int *nr) + unsigned long end, unsigned int flags, + struct page **pages, int *nr) { unsigned long fault_pfn; int nr_start = *nr; fault_pfn = pmd_pfn(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); - if (!__gup_device_huge(fault_pfn, addr, end, pages, nr)) + if (!__gup_device_huge(fault_pfn, addr, end, flags, pages, nr)) return 0; if (unlikely(pmd_val(orig) != pmd_val(*pmdp))) { @@ -1933,13 +1935,14 @@ static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, } static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, - unsigned long end, struct page **pages, int *nr) + unsigned long end, unsigned int flags, + struct page **pages, int *nr) { unsigned long fault_pfn; int nr_start = *nr; fault_pfn = pud_pfn(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); - if (!__gup_device_huge(fault_pfn, addr, end, pages, nr)) + if (!__gup_device_huge(fault_pfn, addr, end, flags, pages, nr)) return 0; if (unlikely(pud_val(orig) != pud_val(*pudp))) { @@ -1950,14 +1953,16 @@ static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, } #else static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, - unsigned long end, struct page **pages, int *nr) + unsigned long end, unsigned int flags, + struct page **pages, int *nr) { BUILD_BUG(); return 0; } static int __gup_device_huge_pud(pud_t pud, pud_t *pudp, unsigned long addr, - unsigned long end, struct page **pages, int *nr) + unsigned long end, unsigned int flags, + struct page **pages, int *nr) { BUILD_BUG(); return 0; @@ -2062,7 +2067,8 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, if (pmd_devmap(orig)) { if (unlikely(flags & FOLL_LONGTERM)) return 0; - return __gup_device_huge_pmd(orig, pmdp, addr, end, pages, nr); + return __gup_device_huge_pmd(orig, pmdp, addr, end, flags, + pages, nr); } refs = 0; @@ -2092,7 +2098,8 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, } static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, - unsigned long end, unsigned int flags, struct page **pages, int *nr) + unsigned long end, unsigned int flags, + struct page **pages, int *nr) { struct page *head, *page; int refs; @@ -2103,7 +2110,8 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, if (pud_devmap(orig)) { if (unlikely(flags & FOLL_LONGTERM)) return 0; - return __gup_device_huge_pud(orig, pudp, addr, end, pages, nr); + return __gup_device_huge_pud(orig, pudp, addr, end, flags, + pages, nr); } refs = 0; From patchwork Tue Nov 12 00:06:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238361 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7EC6916B1 for ; Tue, 12 Nov 2019 00:11:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52D9420840 for ; Tue, 12 Nov 2019 00:11:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="BrEsyttE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727109AbfKLALL (ORCPT ); Mon, 11 Nov 2019 19:11:11 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:3253 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726910AbfKLAHN (ORCPT ); Mon, 11 Nov 2019 19:07:13 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:10 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:06 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Nov 2019 16:07:06 -0800 Received: from HQMAIL107.nvidia.com (172.20.187.13) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:05 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:05 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:05 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard , Christoph Hellwig , "Aneesh Kumar K . V" Subject: [PATCH v3 02/23] mm/gup: factor out duplicate code from four routines Date: Mon, 11 Nov 2019 16:06:39 -0800 Message-ID: <20191112000700.3455038-3-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517170; bh=kJfdBwtxV0Xf/7sPEfLRjg5QuIfiLXYo87o9tgl9dSA=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=BrEsyttE6RAmwKB2dP7t/hBES/LaE75S+oPLzu5r7Y/kro8+cn3Newv+8jmhnecuh M8pIqjj1obr+Rk//EYouq3SWQOmaPTVaz/JRvgWyHkvjTy13z1nMPs1kDmMbzyjy4i B2DtnxHMFX/uC7ck8Y+TAzvF3XL88SsmUr7NyzOGpy0u7RUKqOUw8eOx5DcCuBfGqG sotzZd7RDCoVqxqBS/corUzcJ6EVGB7oX93vLKNtalUTMugHKtxPEADexZRDM+fkzO BcA7dsCfwX4C8fZC3v4YoCmiwJmXmqAvlc0PzjO8cVkU+tfPIs2yiWH/W+Fuvfe7k0 LC9kAMJdb6nyA== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org There are four locations in gup.c that have a fair amount of code duplication. This means that changing one requires making the same changes in four places, not to mention reading the same code four times, and wondering if there are subtle differences. Factor out the common code into static functions, thus reducing the overall line count and the code's complexity. Also, take the opportunity to slightly improve the efficiency of the error cases, by doing a mass subtraction of the refcount, surrounded by get_page()/put_page(). Also, further simplify (slightly), by waiting until the the successful end of each routine, to increment *nr. Reviewed-by: Jérôme Glisse Cc: Ira Weiny Cc: Christoph Hellwig Cc: Aneesh Kumar K.V Signed-off-by: John Hubbard --- mm/gup.c | 104 ++++++++++++++++++++++++------------------------------- 1 file changed, 45 insertions(+), 59 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 85caf76b3012..199da99e8ffc 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1969,6 +1969,34 @@ static int __gup_device_huge_pud(pud_t pud, pud_t *pudp, unsigned long addr, } #endif +static int __record_subpages(struct page *page, unsigned long addr, + unsigned long end, struct page **pages, int nr) +{ + int nr_recorded_pages = 0; + + do { + pages[nr] = page; + nr++; + page++; + nr_recorded_pages++; + } while (addr += PAGE_SIZE, addr != end); + return nr_recorded_pages; +} + +static void put_compound_head(struct page *page, int refs) +{ + /* Do a get_page() first, in case refs == page->_refcount */ + get_page(page); + page_ref_sub(page, refs); + put_page(page); +} + +static void __huge_pt_done(struct page *head, int nr_recorded_pages, int *nr) +{ + *nr += nr_recorded_pages; + SetPageReferenced(head); +} + #ifdef CONFIG_ARCH_HAS_HUGEPD static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end, unsigned long sz) @@ -1998,33 +2026,20 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, /* hugepages are never "special" */ VM_BUG_ON(!pfn_valid(pte_pfn(pte))); - refs = 0; head = pte_page(pte); - page = head + ((addr & (sz-1)) >> PAGE_SHIFT); - do { - VM_BUG_ON(compound_head(page) != head); - pages[*nr] = page; - (*nr)++; - page++; - refs++; - } while (addr += PAGE_SIZE, addr != end); + refs = __record_subpages(page, addr, end, pages, *nr); head = try_get_compound_head(head, refs); - if (!head) { - *nr -= refs; + if (!head) return 0; - } if (unlikely(pte_val(pte) != pte_val(*ptep))) { - /* Could be optimized better */ - *nr -= refs; - while (refs--) - put_page(head); + put_compound_head(head, refs); return 0; } - SetPageReferenced(head); + __huge_pt_done(head, refs, nr); return 1; } @@ -2071,29 +2086,19 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, pages, nr); } - refs = 0; page = pmd_page(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); - do { - pages[*nr] = page; - (*nr)++; - page++; - refs++; - } while (addr += PAGE_SIZE, addr != end); + refs = __record_subpages(page, addr, end, pages, *nr); head = try_get_compound_head(pmd_page(orig), refs); - if (!head) { - *nr -= refs; + if (!head) return 0; - } if (unlikely(pmd_val(orig) != pmd_val(*pmdp))) { - *nr -= refs; - while (refs--) - put_page(head); + put_compound_head(head, refs); return 0; } - SetPageReferenced(head); + __huge_pt_done(head, refs, nr); return 1; } @@ -2114,29 +2119,19 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, pages, nr); } - refs = 0; page = pud_page(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); - do { - pages[*nr] = page; - (*nr)++; - page++; - refs++; - } while (addr += PAGE_SIZE, addr != end); + refs = __record_subpages(page, addr, end, pages, *nr); head = try_get_compound_head(pud_page(orig), refs); - if (!head) { - *nr -= refs; + if (!head) return 0; - } if (unlikely(pud_val(orig) != pud_val(*pudp))) { - *nr -= refs; - while (refs--) - put_page(head); + put_compound_head(head, refs); return 0; } - SetPageReferenced(head); + __huge_pt_done(head, refs, nr); return 1; } @@ -2151,29 +2146,20 @@ static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr, return 0; BUILD_BUG_ON(pgd_devmap(orig)); - refs = 0; + page = pgd_page(orig) + ((addr & ~PGDIR_MASK) >> PAGE_SHIFT); - do { - pages[*nr] = page; - (*nr)++; - page++; - refs++; - } while (addr += PAGE_SIZE, addr != end); + refs = __record_subpages(page, addr, end, pages, *nr); head = try_get_compound_head(pgd_page(orig), refs); - if (!head) { - *nr -= refs; + if (!head) return 0; - } if (unlikely(pgd_val(orig) != pgd_val(*pgdp))) { - *nr -= refs; - while (refs--) - put_page(head); + put_compound_head(head, refs); return 0; } - SetPageReferenced(head); + __huge_pt_done(head, refs, nr); return 1; } From patchwork Tue Nov 12 00:06:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238381 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EDB191864 for ; Tue, 12 Nov 2019 00:11:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB8C82184C for ; Tue, 12 Nov 2019 00:11:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="GkDH7li9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726995AbfKLAHN (ORCPT ); Mon, 11 Nov 2019 19:07:13 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:3257 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726902AbfKLAHM (ORCPT ); Mon, 11 Nov 2019 19:07:12 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:11 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:07 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:07 -0800 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:07 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:06 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:06 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 03/23] mm/gup: move try_get_compound_head() to top, fix minor issues Date: Mon, 11 Nov 2019 16:06:40 -0800 Message-ID: <20191112000700.3455038-4-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517171; bh=5vGfYGjp3s6bW36xq9/Bb46iugaNKE7HlOm7HXQ5wWg=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=GkDH7li9lP7A/uMpxLR/P9FNhMq8JTTMAN0SWpbrJSFjXGyR/2s9DlCPum2PGa7jS 5drAJ2N47vT5h8NKUbzJDgy+l4lgeEnj4eGWzvzqlIlYp5/bn++aheJOdFNX7wAfGI JFW0BhIXxLq2jL3t1c2FtH1mVrBDrEARcO31SdbgzvbdMembdb9e6J0rVv0+jswL2Q m9MWfxq3HHmN1Dge0LLpO6W3G+XeMFrpoGnRwBReM/8tedKtKrqPaeNLNp5pGfn99+ Rf4dT9miWLuHEHaykyiWZaS9DgnEPoNCck1Vo5IUhU1r8GP2qmo/PaOTok7Cj6p+9F d9k7VvHI1voLg== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org An upcoming patch uses try_get_compound_head() more widely, so move it to the top of gup.c. Also fix a tiny spelling error and a checkpatch.pl warning. Signed-off-by: John Hubbard --- mm/gup.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 199da99e8ffc..933524de6249 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -29,6 +29,21 @@ struct follow_page_context { unsigned int page_mask; }; +/* + * Return the compound head page with ref appropriately incremented, + * or NULL if that failed. + */ +static inline struct page *try_get_compound_head(struct page *page, int refs) +{ + struct page *head = compound_head(page); + + if (WARN_ON_ONCE(page_ref_count(head) < 0)) + return NULL; + if (unlikely(!page_cache_add_speculative(head, refs))) + return NULL; + return head; +} + /** * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages * @pages: array of pages to be maybe marked dirty, and definitely released. @@ -1793,20 +1808,6 @@ static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start, } } -/* - * Return the compund head page with ref appropriately incremented, - * or NULL if that failed. - */ -static inline struct page *try_get_compound_head(struct page *page, int refs) -{ - struct page *head = compound_head(page); - if (WARN_ON_ONCE(page_ref_count(head) < 0)) - return NULL; - if (unlikely(!page_cache_add_speculative(head, refs))) - return NULL; - return head; -} - #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, unsigned int flags, struct page **pages, int *nr) From patchwork Tue Nov 12 00:06:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238375 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 553A416B1 for ; Tue, 12 Nov 2019 00:11:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 29DBE2196E for ; Tue, 12 Nov 2019 00:11:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="adfHMgrN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727338AbfKLALY (ORCPT ); Mon, 11 Nov 2019 19:11:24 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:16630 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726908AbfKLAHN (ORCPT ); Mon, 11 Nov 2019 19:07:13 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:07 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:09 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Nov 2019 16:07:09 -0800 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:08 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:07 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:07 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 04/23] mm: devmap: refactor 1-based refcounting for ZONE_DEVICE pages Date: Mon, 11 Nov 2019 16:06:41 -0800 Message-ID: <20191112000700.3455038-5-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517167; bh=eh5PKTqFnv3H2C1oWk46Hm4jlzYBaiSiPR2xbAo8/Xk=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=adfHMgrN5jjkYVKLpULgMMWgAAyNhWrnIEq2gG0krc84wIe5DqW2HFzzxJxJzHIrG Q4SMQIqJPunErE+KDabNclG7+yPRQM1rbHN9kjnmobU9luoWgogwM08Ig6xBrYzT+8 M1Otb8NEwlqrd2K6zNLVLcuzFS2o3KsS+mlQYJu4TNJt8AxTcIQk5KKm3GEA97K6Qs Gnl5NOdsaNBoy4dPOubgCBkbhuzz6aSRrdwtKi2YFqtByoOat5K4PpX4+mgTYRZFJz kwO8BxgUl0DLC6pXM0I8aGV+8wGdM57g3KJobQK8NnZciawV1jrn2TFZRg9Xau0MTU ONfrW7dMbEHRQ== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org An upcoming patch changes and complicates the refcounting and especially the "put page" aspects of it. In order to keep everything clean, refactor the devmap page release routines: * Rename put_devmap_managed_page() to page_is_devmap_managed(), and limit the functionality to "read only": return a bool, with no side effects. * Add a new routine, put_devmap_managed_page(), to handle checking what kind of page it is, and what kind of refcount handling it requires. * Rename __put_devmap_managed_page() to free_devmap_managed_page(), and limit the functionality to unconditionally freeing a devmap page. This is originally based on a separate patch by Ira Weiny, which applied to an early version of the put_user_page() experiments. Since then, Jérôme Glisse suggested the refactoring described above. Suggested-by: Jérôme Glisse Signed-off-by: Ira Weiny Signed-off-by: John Hubbard --- include/linux/mm.h | 27 ++++++++++++++++--- mm/memremap.c | 67 ++++++++++++++++++++-------------------------- 2 files changed, 53 insertions(+), 41 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index a2adf95b3f9c..96228376139c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -967,9 +967,10 @@ static inline bool is_zone_device_page(const struct page *page) #endif #ifdef CONFIG_DEV_PAGEMAP_OPS -void __put_devmap_managed_page(struct page *page); +void free_devmap_managed_page(struct page *page); DECLARE_STATIC_KEY_FALSE(devmap_managed_key); -static inline bool put_devmap_managed_page(struct page *page) + +static inline bool page_is_devmap_managed(struct page *page) { if (!static_branch_unlikely(&devmap_managed_key)) return false; @@ -978,7 +979,6 @@ static inline bool put_devmap_managed_page(struct page *page) switch (page->pgmap->type) { case MEMORY_DEVICE_PRIVATE: case MEMORY_DEVICE_FS_DAX: - __put_devmap_managed_page(page); return true; default: break; @@ -986,6 +986,27 @@ static inline bool put_devmap_managed_page(struct page *page) return false; } +static inline bool put_devmap_managed_page(struct page *page) +{ + bool is_devmap = page_is_devmap_managed(page); + + if (is_devmap) { + int count = page_ref_dec_return(page); + + /* + * devmap page refcounts are 1-based, rather than 0-based: if + * refcount is 1, then the page is free and the refcount is + * stable because nobody holds a reference on the page. + */ + if (count == 1) + free_devmap_managed_page(page); + else if (!count) + __put_page(page); + } + + return is_devmap; +} + #else /* CONFIG_DEV_PAGEMAP_OPS */ static inline bool put_devmap_managed_page(struct page *page) { diff --git a/mm/memremap.c b/mm/memremap.c index 03ccbdfeb697..bc7e2a27d025 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -410,48 +410,39 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn, EXPORT_SYMBOL_GPL(get_dev_pagemap); #ifdef CONFIG_DEV_PAGEMAP_OPS -void __put_devmap_managed_page(struct page *page) +void free_devmap_managed_page(struct page *page) { - int count = page_ref_dec_return(page); + /* Clear Active bit in case of parallel mark_page_accessed */ + __ClearPageActive(page); + __ClearPageWaiters(page); + + mem_cgroup_uncharge(page); /* - * If refcount is 1 then page is freed and refcount is stable as nobody - * holds a reference on the page. + * When a device_private page is freed, the page->mapping field + * may still contain a (stale) mapping value. For example, the + * lower bits of page->mapping may still identify the page as + * an anonymous page. Ultimately, this entire field is just + * stale and wrong, and it will cause errors if not cleared. + * One example is: + * + * migrate_vma_pages() + * migrate_vma_insert_page() + * page_add_new_anon_rmap() + * __page_set_anon_rmap() + * ...checks page->mapping, via PageAnon(page) call, + * and incorrectly concludes that the page is an + * anonymous page. Therefore, it incorrectly, + * silently fails to set up the new anon rmap. + * + * For other types of ZONE_DEVICE pages, migration is either + * handled differently or not done at all, so there is no need + * to clear page->mapping. */ - if (count == 1) { - /* Clear Active bit in case of parallel mark_page_accessed */ - __ClearPageActive(page); - __ClearPageWaiters(page); - - mem_cgroup_uncharge(page); - - /* - * When a device_private page is freed, the page->mapping field - * may still contain a (stale) mapping value. For example, the - * lower bits of page->mapping may still identify the page as - * an anonymous page. Ultimately, this entire field is just - * stale and wrong, and it will cause errors if not cleared. - * One example is: - * - * migrate_vma_pages() - * migrate_vma_insert_page() - * page_add_new_anon_rmap() - * __page_set_anon_rmap() - * ...checks page->mapping, via PageAnon(page) call, - * and incorrectly concludes that the page is an - * anonymous page. Therefore, it incorrectly, - * silently fails to set up the new anon rmap. - * - * For other types of ZONE_DEVICE pages, migration is either - * handled differently or not done at all, so there is no need - * to clear page->mapping. - */ - if (is_device_private_page(page)) - page->mapping = NULL; + if (is_device_private_page(page)) + page->mapping = NULL; - page->pgmap->ops->page_free(page); - } else if (!count) - __put_page(page); + page->pgmap->ops->page_free(page); } -EXPORT_SYMBOL(__put_devmap_managed_page); +EXPORT_SYMBOL(free_devmap_managed_page); #endif /* CONFIG_DEV_PAGEMAP_OPS */ From patchwork Tue Nov 12 00:06:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238315 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8EDAD14E5 for ; Tue, 12 Nov 2019 00:10:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D4422184C for ; Tue, 12 Nov 2019 00:10:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="V83Mm/mg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727530AbfKLAKp (ORCPT ); Mon, 11 Nov 2019 19:10:45 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10614 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726979AbfKLAHO (ORCPT ); Mon, 11 Nov 2019 19:07:14 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:13 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:10 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Nov 2019 16:07:10 -0800 Received: from HQMAIL107.nvidia.com (172.20.187.13) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:09 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:08 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:08 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 05/23] goldish_pipe: rename local pin_user_pages() routine Date: Mon, 11 Nov 2019 16:06:42 -0800 Message-ID: <20191112000700.3455038-6-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517233; bh=OvCIL0+nr8EQ3ucOYL7z+Bd4Y3AXJzaosdg9/Wp2t2k=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=V83Mm/mgD13wOskCVUg3jXnnwavnPQ3ylc/JhyLve0YbkPqUMMHZTXt9R3Coa9qBI 80xP6p17NB70zDrJDKM0H06sAl8/jk3I6sztgeF1r+2JvnRlR/gRrgYjRd7k2qYRvF +etmspepNCoSfoh6DuJ9/Tl8quVDHw6f0ZMNYbPHAmdMqdIErdjTDHj7kfctfYwHYJ JrQM4B4WS9e1j6/4cRSDe44i8Ut0ljDfyI3fIr7hg3xeYD37/uLAn+pj5hfJLOPdfS YfZPx8xiCB4HatUs9wFbCohJOTXKLLcrnHTUpGh/cMLJ3coAlt4cJM6JmF3rNz8d1h pWma1MKSn5Urw== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 1. Avoid naming conflicts: rename local static function from "pin_user_pages()" to "pin_goldfish_pages()". An upcoming patch will introduce a global pin_user_pages() function. Reviewed-by: Jérôme Glisse Reviewed-by: Ira Weiny Signed-off-by: John Hubbard --- drivers/platform/goldfish/goldfish_pipe.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c index cef0133aa47a..7ed2a21a0bac 100644 --- a/drivers/platform/goldfish/goldfish_pipe.c +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -257,12 +257,12 @@ static int goldfish_pipe_error_convert(int status) } } -static int pin_user_pages(unsigned long first_page, - unsigned long last_page, - unsigned int last_page_size, - int is_write, - struct page *pages[MAX_BUFFERS_PER_COMMAND], - unsigned int *iter_last_page_size) +static int pin_goldfish_pages(unsigned long first_page, + unsigned long last_page, + unsigned int last_page_size, + int is_write, + struct page *pages[MAX_BUFFERS_PER_COMMAND], + unsigned int *iter_last_page_size) { int ret; int requested_pages = ((last_page - first_page) >> PAGE_SHIFT) + 1; @@ -354,9 +354,9 @@ static int transfer_max_buffers(struct goldfish_pipe *pipe, if (mutex_lock_interruptible(&pipe->lock)) return -ERESTARTSYS; - pages_count = pin_user_pages(first_page, last_page, - last_page_size, is_write, - pipe->pages, &iter_last_page_size); + pages_count = pin_goldfish_pages(first_page, last_page, + last_page_size, is_write, + pipe->pages, &iter_last_page_size); if (pages_count < 0) { mutex_unlock(&pipe->lock); return pages_count; From patchwork Tue Nov 12 00:06:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238363 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5E95F16B1 for ; Tue, 12 Nov 2019 00:11:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C2332196E for ; Tue, 12 Nov 2019 00:11:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="KhLyNKkC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727126AbfKLAHN (ORCPT ); Mon, 11 Nov 2019 19:07:13 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10606 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726952AbfKLAHM (ORCPT ); Mon, 11 Nov 2019 19:07:12 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:13 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:11 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:11 -0800 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:10 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:09 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:09 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 06/23] IB/umem: use get_user_pages_fast() to pin DMA pages Date: Mon, 11 Nov 2019 16:06:43 -0800 Message-ID: <20191112000700.3455038-7-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517233; bh=PPNQFWxgYbSBG60Oh3uZy3iaVFj8VG12aJVlvrNgBtA=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=KhLyNKkCzhj34VhXuUGSIyHKFQpNlddwQKTMNRSggrE3w/lk5jSmv2ZPbZbufxy2D DwaHNn9deLnwb+9S3bnPYQt2Y8a3N/x+xRd7lyCZjJtBVXS48USN4LyP/T0wSL31A9 PHqCuFVCls1I4InDR/rmL4jQ59eW6S2dzy1GP6jDulz/TY3IS2beeDr/v5uOBQkkt8 cgTue/HPtPzjoomkooCtsjx52sbOSGnuwdu4CRFlEX4ieAvkNbohjJOFrY+GPgctFC eybfSvcxdSFjY5MlzuusMY1vIOFT2942rU66o5rV0txugAXwkPygIU4TkcCtTuqA4d LT2EnhJx44zxw== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org And get rid of the mmap_sem calls, as part of that. Note that get_user_pages_fast() will, if necessary, fall back to __gup_longterm_unlocked(), which takes the mmap_sem as needed. Reviewed-by: Ira Weiny Cc: Jason Gunthorpe Signed-off-by: John Hubbard --- drivers/infiniband/core/umem.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 24244a2f68cc..3d664a2539eb 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -271,16 +271,13 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, sg = umem->sg_head.sgl; while (npages) { - down_read(&mm->mmap_sem); - ret = get_user_pages(cur_base, - min_t(unsigned long, npages, - PAGE_SIZE / sizeof (struct page *)), - gup_flags | FOLL_LONGTERM, - page_list, NULL); - if (ret < 0) { - up_read(&mm->mmap_sem); + ret = get_user_pages_fast(cur_base, + min_t(unsigned long, npages, + PAGE_SIZE / + sizeof(struct page *)), + gup_flags | FOLL_LONGTERM, page_list); + if (ret < 0) goto umem_release; - } cur_base += ret * PAGE_SIZE; npages -= ret; @@ -288,8 +285,6 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, sg = ib_umem_add_sg_table(sg, page_list, ret, dma_get_max_seg_size(context->device->dma_device), &umem->sg_nents); - - up_read(&mm->mmap_sem); } sg_mark_end(sg); From patchwork Tue Nov 12 00:06:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238293 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DB0ED14E5 for ; Tue, 12 Nov 2019 00:10:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B923321872 for ; Tue, 12 Nov 2019 00:10:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="RlH9aqnq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726954AbfKLAKG (ORCPT ); Mon, 11 Nov 2019 19:10:06 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10662 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727348AbfKLAHR (ORCPT ); Mon, 11 Nov 2019 19:07:17 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:15 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:12 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:12 -0800 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:11 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:11 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:10 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard , Hans Verkuil Subject: [PATCH v3 07/23] media/v4l2-core: set pages dirty upon releasing DMA buffers Date: Mon, 11 Nov 2019 16:06:44 -0800 Message-ID: <20191112000700.3455038-8-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517235; bh=baa1oHQC+1Mr0fCveGP8H7qjkYYEgQstEl5cvxrT4lI=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=RlH9aqnqOSW+i3r1ZNXVi188qkv8oPSHEHjP9TUEYUBYLbJPXbCpIeoixfuoEUqmI LJQtooBZONbMwl8oDlAORux6L1NKfifp27oCOAjTVolvjx6x9UZZFR2KckBFFMRmgl 7ucrDkIOQN1npJzTWI7Ie8VFWM02QId/hYOgJ3myD0hMMeVv/fPJ718f4N4x/Nio9D nFCya3Va0g2AaF10Bt3vATun/e/fRWeVe3HmbkEqJ2DQKgHOYzNMdmbeE1eZQEGUaw vwJeZf5SUFYrVGVb3dcPAmWcGTCefk/PAeXugQwb4JRf9NSmFCSds9KRkQl3pKX4bn 5prvXiV+C9UDw== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org After DMA is complete, and the device and CPU caches are synchronized, it's still required to mark the CPU pages as dirty, if the data was coming from the device. However, this driver was just issuing a bare put_page() call, without any set_page_dirty*() call. Fix the problem, by calling set_page_dirty_lock() if the CPU pages were potentially receiving data from the device. Acked-by: Hans Verkuil Cc: Mauro Carvalho Chehab Signed-off-by: John Hubbard --- drivers/media/v4l2-core/videobuf-dma-sg.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c index 66a6c6c236a7..28262190c3ab 100644 --- a/drivers/media/v4l2-core/videobuf-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf-dma-sg.c @@ -349,8 +349,11 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma) BUG_ON(dma->sglen); if (dma->pages) { - for (i = 0; i < dma->nr_pages; i++) + for (i = 0; i < dma->nr_pages; i++) { + if (dma->direction == DMA_FROM_DEVICE) + set_page_dirty_lock(dma->pages[i]); put_page(dma->pages[i]); + } kfree(dma->pages); dma->pages = NULL; } From patchwork Tue Nov 12 00:06:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238269 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 70A1616B1 for ; Tue, 12 Nov 2019 00:09:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E72E2184C for ; Tue, 12 Nov 2019 00:09:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="SJ2uh291" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727420AbfKLAHT (ORCPT ); Mon, 11 Nov 2019 19:07:19 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:3297 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726949AbfKLAHS (ORCPT ); Mon, 11 Nov 2019 19:07:18 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:16 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:12 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:12 -0800 Received: from HQMAIL107.nvidia.com (172.20.187.13) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:12 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:11 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:11 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 08/23] vfio, mm: fix get_user_pages_remote() and FOLL_LONGTERM Date: Mon, 11 Nov 2019 16:06:45 -0800 Message-ID: <20191112000700.3455038-9-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517177; bh=LHd6nlstYt/+WO2arS2xO7M4BDaQ4oXhsosl4/alSFg=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=SJ2uh291o0n2KAathWWaARa6MvN+m/A73UL04mBGFpYz9dwZwEu2YOKZK/z6oR36f S4MmrBohFcW7M4U4sGwLAQQaa4ErNxr5zszFsv1ppGBtK5nFe0oidXZ1r/1d+C5hHD 7OdWLPmiW5F6FVC/3nIr5wwa+GbS2yQdK9nseWpjIMdx642Wxvb5Kkid/PLVxBV3h0 OGPpdpsgYBaWnEIgbpCi7rX0MmoFtgOyBhqm3y6VOtt9bGAvDRddLo4gcp8LgfWb9W RGx06m/cZaFaW7nNL6zPl1lRK04yV8Qj7tUjurbVty1S8No3Te9OtVs5tQeXtoroeI mB7ag0CyWpHAw== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org As it says in the updated comment in gup.c: current FOLL_LONGTERM behavior is incompatible with FAULT_FLAG_ALLOW_RETRY because of the FS DAX check requirement on vmas. However, the corresponding restriction in get_user_pages_remote() was slightly stricter than is actually required: it forbade all FOLL_LONGTERM callers, but we can actually allow FOLL_LONGTERM callers that do not set the "locked" arg. Update the code and comments accordingly, and update the VFIO caller to take advantage of this, fixing a bug as a result: the VFIO caller is logically a FOLL_LONGTERM user. Thanks to Jason Gunthorpe for pointing out a clean way to fix this. Suggested-by: Jason Gunthorpe Cc: Jerome Glisse Cc: Ira Weiny Signed-off-by: John Hubbard --- drivers/vfio/vfio_iommu_type1.c | 30 +++++++++++++----------------- mm/gup.c | 13 ++++++++----- 2 files changed, 21 insertions(+), 22 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index d864277ea16f..017689b7c32b 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -348,24 +348,20 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, flags |= FOLL_WRITE; down_read(&mm->mmap_sem); - if (mm == current->mm) { - ret = get_user_pages(vaddr, 1, flags | FOLL_LONGTERM, page, - vmas); - } else { - ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page, - vmas, NULL); - /* - * The lifetime of a vaddr_get_pfn() page pin is - * userspace-controlled. In the fs-dax case this could - * lead to indefinite stalls in filesystem operations. - * Disallow attempts to pin fs-dax pages via this - * interface. - */ - if (ret > 0 && vma_is_fsdax(vmas[0])) { - ret = -EOPNOTSUPP; - put_page(page[0]); - } + ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, + page, vmas, NULL); + /* + * The lifetime of a vaddr_get_pfn() page pin is + * userspace-controlled. In the fs-dax case this could + * lead to indefinite stalls in filesystem operations. + * Disallow attempts to pin fs-dax pages via this + * interface. + */ + if (ret > 0 && vma_is_fsdax(vmas[0])) { + ret = -EOPNOTSUPP; + put_page(page[0]); } + up_read(&mm->mmap_sem); if (ret == 1) { diff --git a/mm/gup.c b/mm/gup.c index 933524de6249..cfe6dc5fc343 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1167,13 +1167,16 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, struct vm_area_struct **vmas, int *locked) { /* - * FIXME: Current FOLL_LONGTERM behavior is incompatible with + * Current FOLL_LONGTERM behavior is incompatible with * FAULT_FLAG_ALLOW_RETRY because of the FS DAX check requirement on - * vmas. As there are no users of this flag in this call we simply - * disallow this option for now. + * vmas. However, this only comes up if locked is set, and there are + * callers that do request FOLL_LONGTERM, but do not set locked. So, + * allow what we can. */ - if (WARN_ON_ONCE(gup_flags & FOLL_LONGTERM)) - return -EINVAL; + if (gup_flags & FOLL_LONGTERM) { + if (WARN_ON_ONCE(locked)) + return -EINVAL; + } return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, locked, From patchwork Tue Nov 12 00:06:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238251 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 350B716B1 for ; Tue, 12 Nov 2019 00:09:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 098522196E for ; Tue, 12 Nov 2019 00:09:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="IBjil0PY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727491AbfKLAJ0 (ORCPT ); Mon, 11 Nov 2019 19:09:26 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10683 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727437AbfKLAHZ (ORCPT ); Mon, 11 Nov 2019 19:07:25 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:17 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:15 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:15 -0800 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:14 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:13 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:13 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard , Mike Rapoport Subject: [PATCH v3 09/23] mm/gup: introduce pin_user_pages*() and FOLL_PIN Date: Mon, 11 Nov 2019 16:06:46 -0800 Message-ID: <20191112000700.3455038-10-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517238; bh=NlHV4Xgok5ZU8TaAFKmeS4btcWTwEZUcH8SPgzpp278=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=IBjil0PY8dLzuMCfXj7TyQrUoGPtXXmvJPW5S5UVpPPxr/c8Auc8cTknHgDnUQmiM r41Pao3cPu2aP/z6b0HX0dwlot1Zf87P6OvM52CTfp3ByW1G97jsg2RF/QuVE1iqT9 M09lOgDs5F28KEZbISw2kiYTCiwsaOu23r3uX7zLz+29aCyCC4+FgojbZZpRXpLP9E 2FYsE5eIgqUFZ8CWlKdc6lbKaILHH2sNNqnJaSC8eJQEDOuXAKOTXD+6ltqxBNcZ1G fcKTpa2OnV+JSM/ggk7AfIx7nQAyjrzy137wAeU/PiSIL9XnkC5LXr/HjOv2fDsXbW WERT3Bm4wdlBw== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Introduce pin_user_pages*() variations of get_user_pages*() calls, and also pin_longterm_pages*() variations. These variants all set FOLL_PIN, which is also introduced, and thoroughly documented. The pin_longterm*() variants also set FOLL_LONGTERM, in addition to FOLL_PIN: pin_user_pages() pin_user_pages_remote() pin_user_pages_fast() pin_longterm_pages() pin_longterm_pages_remote() pin_longterm_pages_fast() All pages that are pinned via the above calls, must be unpinned via put_user_page(). The underlying rules are: * These are gup-internal flags, so the call sites should not directly set FOLL_PIN nor FOLL_LONGTERM. That behavior is enforced with assertions, for the new FOLL_PIN flag. However, for the pre-existing FOLL_LONGTERM flag, which has some call sites that still directly set FOLL_LONGTERM, there is no assertion yet. * Call sites that want to indicate that they are going to do DirectIO ("DIO") or something with similar characteristics, should call a get_user_pages()-like wrapper call that sets FOLL_PIN. These wrappers will: * Start with "pin_user_pages" instead of "get_user_pages". That makes it easy to find and audit the call sites. * Set FOLL_PIN * For pages that are received via FOLL_PIN, those pages must be returned via put_user_page(). Thanks to Jan Kara and Vlastimil Babka for explaining the 4 cases in this documentation. (I've reworded it and expanded upon it.) Reviewed-by: Jérôme Glisse Cc: Mike Rapoport Cc: Jonathan Corbet Cc: Ira Weiny Signed-off-by: John Hubbard Reviewed-by: Mike Rapoport # Documentation --- Documentation/core-api/index.rst | 1 + Documentation/core-api/pin_user_pages.rst | 218 ++++++++++++++++++ include/linux/mm.h | 62 +++++- mm/gup.c | 260 ++++++++++++++++++++-- 4 files changed, 514 insertions(+), 27 deletions(-) create mode 100644 Documentation/core-api/pin_user_pages.rst diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst index ab0eae1c153a..413f7d7c8642 100644 --- a/Documentation/core-api/index.rst +++ b/Documentation/core-api/index.rst @@ -31,6 +31,7 @@ Core utilities generic-radix-tree memory-allocation mm-api + pin_user_pages gfp_mask-from-fs-io timekeeping boot-time-mm diff --git a/Documentation/core-api/pin_user_pages.rst b/Documentation/core-api/pin_user_pages.rst new file mode 100644 index 000000000000..ce819e709435 --- /dev/null +++ b/Documentation/core-api/pin_user_pages.rst @@ -0,0 +1,218 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================================================== +pin_user_pages() and related calls +==================================================== + +.. contents:: :local: + +Overview +======== + +This document describes the following functions: :: + + pin_user_pages + pin_user_pages_fast + pin_user_pages_remote + + pin_longterm_pages + pin_longterm_pages_fast + pin_longterm_pages_remote + +Basic description of FOLL_PIN +============================= + +FOLL_PIN and FOLL_LONGTERM are flags that can be passed to the get_user_pages*() +("gup") family of functions. FOLL_PIN has significant interactions and +interdependencies with FOLL_LONGTERM, so both are covered here. + +Both FOLL_PIN and FOLL_LONGTERM are internal to gup, meaning that neither +FOLL_PIN nor FOLL_LONGTERM should not appear at the gup call sites. This allows +the associated wrapper functions (pin_user_pages() and others) to set the +correct combination of these flags, and to check for problems as well. + +FOLL_PIN and FOLL_GET are mutually exclusive for a given gup call. However, +multiple threads and call sites are free to pin the same struct pages, via both +FOLL_PIN and FOLL_GET. It's just the call site that needs to choose one or the +other, not the struct page(s). + +The FOLL_PIN implementation is nearly the same as FOLL_GET, except that FOLL_PIN +uses a different reference counting technique. + +FOLL_PIN is a prerequisite to FOLL_LONGTGERM. Another way of saying that is, +FOLL_LONGTERM is a specific case, more restrictive case of FOLL_PIN. + +Which flags are set by each wrapper +=================================== + +Only FOLL_PIN and FOLL_LONGTERM are covered here. These flags are added to +whatever flags the caller provides:: + + Function gup flags (FOLL_PIN or FOLL_LONGTERM only) + -------- ------------------------------------------ + pin_user_pages FOLL_PIN + pin_user_pages_fast FOLL_PIN + pin_user_pages_remote FOLL_PIN + + pin_longterm_pages FOLL_PIN | FOLL_LONGTERM + pin_longterm_pages_fast FOLL_PIN | FOLL_LONGTERM + pin_longterm_pages_remote FOLL_PIN | FOLL_LONGTERM + +Tracking dma-pinned pages +========================= + +Some of the key design constraints, and solutions, for tracking dma-pinned +pages: + +* An actual reference count, per struct page, is required. This is because + multiple processes may pin and unpin a page. + +* False positives (reporting that a page is dma-pinned, when in fact it is not) + are acceptable, but false negatives are not. + +* struct page may not be increased in size for this, and all fields are already + used. + +* Given the above, we can overload the page->_refcount field by using, sort of, + the upper bits in that field for a dma-pinned count. "Sort of", means that, + rather than dividing page->_refcount into bit fields, we simple add a medium- + large value (GUP_PIN_COUNTING_BIAS, initially chosen to be 1024: 10 bits) to + page->_refcount. This provides fuzzy behavior: if a page has get_page() called + on it 1024 times, then it will appear to have a single dma-pinned count. + And again, that's acceptable. + +This also leads to limitations: there are only 31-10==21 bits available for a +counter that increments 10 bits at a time. + +TODO: for 1GB and larger huge pages, this is cutting it close. That's because +when pin_user_pages() follows such pages, it increments the head page by "1" +(where "1" used to mean "+1" for get_user_pages(), but now means "+1024" for +pin_user_pages()) for each tail page. So if you have a 1GB huge page: + +* There are 256K (18 bits) worth of 4 KB tail pages. +* There are 21 bits available to count up via GUP_PIN_COUNTING_BIAS (that is, + 10 bits at a time) +* There are 21 - 18 == 3 bits available to count. Except that there aren't, + because you need to allow for a few normal get_page() calls on the head page, + as well. Fortunately, the approach of using addition, rather than "hard" + bitfields, within page->_refcount, allows for sharing these bits gracefully. + But we're still looking at about 8 references. + +This, however, is a missing feature more than anything else, because it's easily +solved by addressing an obvious inefficiency in the original get_user_pages() +approach of retrieving pages: stop treating all the pages as if they were +PAGE_SIZE. Retrieve huge pages as huge pages. The callers need to be aware of +this, so some work is required. Once that's in place, this limitation mostly +disappears from view, because there will be ample refcounting range available. + +* Callers must specifically request "dma-pinned tracking of pages". In other + words, just calling get_user_pages() will not suffice; a new set of functions, + pin_user_page() and related, must be used. + +FOLL_PIN, FOLL_GET, FOLL_LONGTERM: when to use which flags +========================================================== + +Thanks to Jan Kara, Vlastimil Babka and several other -mm people, for describing +these categories: + +CASE 1: Direct IO (DIO) +----------------------- +There are GUP references to pages that are serving +as DIO buffers. These buffers are needed for a relatively short time (so they +are not "long term"). No special synchronization with page_mkclean() or +munmap() is provided. Therefore, flags to set at the call site are: :: + + FOLL_PIN + +...but rather than setting FOLL_PIN directly, call sites should use one of +the pin_user_pages*() routines that set FOLL_PIN. + +CASE 2: RDMA +------------ +There are GUP references to pages that are serving as DMA +buffers. These buffers are needed for a long time ("long term"). No special +synchronization with page_mkclean() or munmap() is provided. Therefore, flags +to set at the call site are: :: + + FOLL_PIN | FOLL_LONGTERM + +NOTE: Some pages, such as DAX pages, cannot be pinned with longterm pins. That's +because DAX pages do not have a separate page cache, and so "pinning" implies +locking down file system blocks, which is not (yet) supported in that way. + +CASE 3: Hardware with page faulting support +------------------------------------------- +Here, a well-written driver doesn't normally need to pin pages at all. However, +if the driver does choose to do so, it can register MMU notifiers for the range, +and will be called back upon invalidation. Either way (avoiding page pinning, or +using MMU notifiers to unpin upon request), there is proper synchronization with +both filesystem and mm (page_mkclean(), munmap(), etc). + +Therefore, neither flag needs to be set. + +In this case, ideally, neither get_user_pages() nor pin_user_pages() should be +called. Instead, the software should be written so that it does not pin pages. +This allows mm and filesystems to operate more efficiently and reliably. + +CASE 4: Pinning for struct page manipulation only +------------------------------------------------- +Here, normal GUP calls are sufficient, so neither flag needs to be set. + +page_dma_pinned(): the whole point of pinning +============================================= + +The whole point of marking pages as "DMA-pinned" or "gup-pinned" is to be able +to query, "is this page DMA-pinned?" That allows code such as page_mkclean() +(and file system writeback code in general) to make informed decisions about +what to do when a page cannot be unmapped due to such pins. + +What to do in those cases is the subject of a years-long series of discussions +and debates (see the References at the end of this document). It's a TODO item +here: fill in the details once that's worked out. Meanwhile, it's safe to say +that having this available: :: + + static inline bool page_dma_pinned(struct page *page) + +...is a prerequisite to solving the long-running gup+DMA problem. + +Another way of thinking about FOLL_GET, FOLL_PIN, and FOLL_LONGTERM +=================================================================== + +Another way of thinking about these flags is as a progression of restrictions: +FOLL_GET is for struct page manipulation, without affecting the data that the +struct page refers to. FOLL_PIN is a *replacement* for FOLL_GET, and is for +short term pins on pages whose data *will* get accessed. As such, FOLL_PIN is +a "more severe" form of pinning. And finally, FOLL_LONGTERM is an even more +restrictive case that has FOLL_PIN as a prerequisite: this is for pages that +will be pinned longterm, and whose data will be accessed. + +Unit testing +============ +This file:: + + tools/testing/selftests/vm/gup_benchmark.c + +has the following new calls to exercise the new pin*() wrapper functions: + +* PIN_FAST_BENCHMARK (./gup_benchmark -a) +* PIN_LONGTERM_BENCHMARK (./gup_benchmark -a) +* PIN_BENCHMARK (./gup_benchmark -a) + +You can monitor how many total dma-pinned pages have been acquired and released +since the system was booted, via two new /proc/vmstat entries: :: + + /proc/vmstat/nr_foll_pin_requested + /proc/vmstat/nr_foll_pin_requested + +Those are both going to show zero, unless CONFIG_DEBUG_VM is set. This is +because there is a noticeable performance drop in put_user_page(), when they +are activated. + +References +========== + +* `Some slow progress on get_user_pages() (Apr 2, 2019) `_ +* `DMA and get_user_pages() (LPC: Dec 12, 2018) `_ +* `The trouble with get_user_pages() (Apr 30, 2018) `_ + +John Hubbard, October, 2019 diff --git a/include/linux/mm.h b/include/linux/mm.h index 96228376139c..11e0086d64a4 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1542,9 +1542,23 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, struct vm_area_struct **vmas, int *locked); +long pin_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, unsigned long nr_pages, + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas, int *locked); +long pin_longterm_pages_remote(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, unsigned long nr_pages, + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas, int *locked); long get_user_pages(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, struct vm_area_struct **vmas); +long pin_user_pages(unsigned long start, unsigned long nr_pages, + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas); +long pin_longterm_pages(unsigned long start, unsigned long nr_pages, + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas); long get_user_pages_locked(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, int *locked); long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, @@ -1552,6 +1566,10 @@ long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages, int get_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages); +int pin_user_pages_fast(unsigned long start, int nr_pages, + unsigned int gup_flags, struct page **pages); +int pin_longterm_pages_fast(unsigned long start, int nr_pages, + unsigned int gup_flags, struct page **pages); int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc); int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc, @@ -2610,13 +2628,15 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, #define FOLL_ANON 0x8000 /* don't do file mappings */ #define FOLL_LONGTERM 0x10000 /* mapping lifetime is indefinite: see below */ #define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */ +#define FOLL_PIN 0x40000 /* pages must be released via put_user_page() */ /* - * NOTE on FOLL_LONGTERM: + * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each + * other. Here is what they mean, and how to use them: * * FOLL_LONGTERM indicates that the page will be held for an indefinite time - * period _often_ under userspace control. This is contrasted with - * iov_iter_get_pages() where usages which are transient. + * period _often_ under userspace control. This is in contrast to + * iov_iter_get_pages(), where usages which are transient. * * FIXME: For pages which are part of a filesystem, mappings are subject to the * lifetime enforced by the filesystem and we need guarantees that longterm @@ -2631,11 +2651,41 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, * Currently only get_user_pages() and get_user_pages_fast() support this flag * and calls to get_user_pages_[un]locked are specifically not allowed. This * is due to an incompatibility with the FS DAX check and - * FAULT_FLAG_ALLOW_RETRY + * FAULT_FLAG_ALLOW_RETRY. * - * In the CMA case: longterm pins in a CMA region would unnecessarily fragment - * that region. And so CMA attempts to migrate the page before pinning when + * In the CMA case: long term pins in a CMA region would unnecessarily fragment + * that region. And so, CMA attempts to migrate the page before pinning, when * FOLL_LONGTERM is specified. + * + * FOLL_PIN indicates that a special kind of tracking (not just page->_refcount, + * but an additional pin counting system) will be invoked. This is intended for + * anything that gets a page reference and then touches page data (for example, + * Direct IO). This lets the filesystem know that some non-file-system entity is + * potentially changing the pages' data. In contrast to FOLL_GET (whose pages + * are released via put_page()), FOLL_PIN pages must be released, ultimately, by + * a call to put_user_page(). + * + * FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different + * and separate refcounting mechanisms, however, and that means that each has + * its own acquire and release mechanisms: + * + * FOLL_GET: get_user_pages*() to acquire, and put_page() to release. + * + * FOLL_PIN: pin_user_pages*() or pin_longterm_pages*() to acquire, and + * put_user_pages to release. + * + * FOLL_PIN and FOLL_GET are mutually exclusive for a given function call. + * (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based + * calls applied to them, and that's perfectly OK. This is a constraint on the + * callers, not on the pages.) + * + * FOLL_PIN and FOLL_LONGTERM should be set internally by the pin_user_page*() + * and pin_longterm_*() APIs, never directly by the caller. That's in order to + * help avoid mismatches when releasing pages: get_user_pages*() pages must be + * released via put_page(), while pin_user_pages*() pages must be released via + * put_user_page(). + * + * Please see Documentation/vm/pin_user_pages.rst for more information. */ static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags) diff --git a/mm/gup.c b/mm/gup.c index cfe6dc5fc343..ea31810da828 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -194,6 +194,10 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, spinlock_t *ptl; pte_t *ptep, pte; + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == + (FOLL_PIN | FOLL_GET))) + return ERR_PTR(-EINVAL); retry: if (unlikely(pmd_bad(*pmd))) return no_page_table(vma, flags); @@ -805,7 +809,7 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, start = untagged_addr(start); - VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); + VM_BUG_ON(!!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN))); /* * If FOLL_FORCE is set then do not force a full fault as the hinting @@ -1029,7 +1033,16 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, BUG_ON(*locked != 1); } - if (pages) + /* + * FOLL_PIN and FOLL_GET are mutually exclusive. Traditional behavior + * is to set FOLL_GET if the caller wants pages[] filled in (but has + * carelessly failed to specify FOLL_GET), so keep doing that, but only + * for FOLL_GET, not for the newer FOLL_PIN. + * + * FOLL_PIN always expects pages to be non-null, but no need to assert + * that here, as any failures will be obvious enough. + */ + if (pages && !(flags & FOLL_PIN)) flags |= FOLL_GET; pages_done = 0; @@ -1166,6 +1179,14 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, unsigned int gup_flags, struct page **pages, struct vm_area_struct **vmas, int *locked) { + /* + * FOLL_PIN must only be set internally by the pin_user_page*() and + * pin_longterm_*() APIs, never directly by the caller, so enforce that + * with an assertion: + */ + if (WARN_ON_ONCE(gup_flags & FOLL_PIN)) + return -EINVAL; + /* * Current FOLL_LONGTERM behavior is incompatible with * FAULT_FLAG_ALLOW_RETRY because of the FS DAX check requirement on @@ -1626,6 +1647,14 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, unsigned int gup_flags, struct page **pages, struct vm_area_struct **vmas) { + /* + * FOLL_PIN must only be set internally by the pin_user_page*() and + * pin_longterm_*() APIs, never directly by the caller, so enforce that + * with an assertion: + */ + if (WARN_ON_ONCE(gup_flags & FOLL_PIN)) + return -EINVAL; + return __gup_longterm_locked(current, current->mm, start, nr_pages, pages, vmas, gup_flags | FOLL_TOUCH); } @@ -2377,29 +2406,14 @@ static int __gup_longterm_unlocked(unsigned long start, int nr_pages, return ret; } -/** - * get_user_pages_fast() - pin user pages in memory - * @start: starting user address - * @nr_pages: number of pages from start to pin - * @gup_flags: flags modifying pin behaviour - * @pages: array that receives pointers to the pages pinned. - * Should be at least nr_pages long. - * - * Attempt to pin user pages in memory without taking mm->mmap_sem. - * If not successful, it will fall back to taking the lock and - * calling get_user_pages(). - * - * Returns number of pages pinned. This may be fewer than the number - * requested. If nr_pages is 0 or negative, returns 0. If no pages - * were pinned, returns -errno. - */ -int get_user_pages_fast(unsigned long start, int nr_pages, - unsigned int gup_flags, struct page **pages) +static int internal_get_user_pages_fast(unsigned long start, int nr_pages, + unsigned int gup_flags, + struct page **pages) { unsigned long addr, len, end; int nr = 0, ret = 0; - if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM))) + if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM | FOLL_PIN))) return -EINVAL; start = untagged_addr(start) & PAGE_MASK; @@ -2439,4 +2453,208 @@ int get_user_pages_fast(unsigned long start, int nr_pages, return ret; } + +/** + * get_user_pages_fast() - pin user pages in memory + * @start: starting user address + * @nr_pages: number of pages from start to pin + * @gup_flags: flags modifying pin behaviour + * @pages: array that receives pointers to the pages pinned. + * Should be at least nr_pages long. + * + * Attempt to pin user pages in memory without taking mm->mmap_sem. + * If not successful, it will fall back to taking the lock and + * calling get_user_pages(). + * + * Returns number of pages pinned. This may be fewer than the number requested. + * If nr_pages is 0 or negative, returns 0. If no pages were pinned, returns + * -errno. + */ +int get_user_pages_fast(unsigned long start, int nr_pages, + unsigned int gup_flags, struct page **pages) +{ + /* + * FOLL_PIN must only be set internally by the pin_user_page*() and + * pin_longterm_*() APIs, never directly by the caller, so enforce that: + */ + if (WARN_ON_ONCE(gup_flags & FOLL_PIN)) + return -EINVAL; + + return internal_get_user_pages_fast(start, nr_pages, gup_flags, pages); +} EXPORT_SYMBOL_GPL(get_user_pages_fast); + +/** + * pin_user_pages_fast() - pin user pages in memory without taking locks + * + * Nearly the same as get_user_pages_fast(), except that FOLL_PIN is set. See + * get_user_pages_fast() for documentation on the function arguments, because + * the arguments here are identical. + * + * FOLL_PIN means that the pages must be released via put_user_page(). Please + * see Documentation/vm/pin_user_pages.rst for further details. + * + * This is intended for Case 1 (DIO) in Documentation/vm/pin_user_pages.rst. It + * is NOT intended for Case 2 (RDMA: long-term pins). + */ +int pin_user_pages_fast(unsigned long start, int nr_pages, + unsigned int gup_flags, struct page **pages) +{ + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return -EINVAL; + + gup_flags |= FOLL_PIN; + return internal_get_user_pages_fast(start, nr_pages, gup_flags, pages); +} +EXPORT_SYMBOL_GPL(pin_user_pages_fast); + +/** + * pin_longterm_pages_fast() - pin user pages in memory without taking locks + * + * Nearly the same as get_user_pages_fast(), except that FOLL_PIN and + * FOLL_LONGTERM are set. See get_user_pages_fast() for documentation on the + * function arguments, because the arguments here are identical. + * + * FOLL_PIN means that the pages must be released via put_user_page(). Please + * see Documentation/vm/pin_user_pages.rst for further details. + * + * FOLL_LONGTERM means that the pages are being pinned for "long term" use, + * typically by a non-CPU device, and we cannot be sure that waiting for a + * pinned page to become unpin will be effective. + * + * This is intended for Case 2 (RDMA: long-term pins) of the FOLL_PIN + * documentation. + */ +int pin_longterm_pages_fast(unsigned long start, int nr_pages, + unsigned int gup_flags, struct page **pages) +{ + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return -EINVAL; + + gup_flags |= (FOLL_PIN | FOLL_LONGTERM); + return internal_get_user_pages_fast(start, nr_pages, gup_flags, pages); +} +EXPORT_SYMBOL_GPL(pin_longterm_pages_fast); + +/** + * pin_user_pages_remote() - pin pages of a remote process (task != current) + * + * Nearly the same as get_user_pages_remote(), except that FOLL_PIN is set. See + * get_user_pages_remote() for documentation on the function arguments, because + * the arguments here are identical. + * + * FOLL_PIN means that the pages must be released via put_user_page(). Please + * see Documentation/vm/pin_user_pages.rst for details. + * + * This is intended for Case 1 (DIO) in Documentation/vm/pin_user_pages.rst. It + * is NOT intended for Case 2 (RDMA: long-term pins). + */ +long pin_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, unsigned long nr_pages, + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas, int *locked) +{ + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return -EINVAL; + + gup_flags |= FOLL_TOUCH | FOLL_REMOTE | FOLL_PIN; + + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + locked, gup_flags); +} +EXPORT_SYMBOL(pin_user_pages_remote); + +/** + * pin_longterm_pages_remote() - pin pages of a remote process (task != current) + * + * Nearly the same as get_user_pages_remote(), but note that FOLL_TOUCH is not + * set, and FOLL_PIN and FOLL_LONGTERM are set. See get_user_pages_remote() for + * documentation on the function arguments, because the arguments here are + * identical. + * + * FOLL_PIN means that the pages must be released via put_user_page(). Please + * see Documentation/vm/pin_user_pages.rst for further details. + * + * FOLL_LONGTERM means that the pages are being pinned for "long term" use, + * typically by a non-CPU device, and we cannot be sure that waiting for a + * pinned page to become unpin will be effective. + * + * This is intended for Case 2 (RDMA: long-term pins) in + * Documentation/vm/pin_user_pages.rst. + */ +long pin_longterm_pages_remote(struct task_struct *tsk, struct mm_struct *mm, + unsigned long start, unsigned long nr_pages, + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas, int *locked) +{ + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return -EINVAL; + + gup_flags |= FOLL_LONGTERM | FOLL_REMOTE | FOLL_PIN; + + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + locked, gup_flags); +} +EXPORT_SYMBOL(pin_longterm_pages_remote); + +/** + * pin_user_pages() - pin user pages in memory for use by other devices + * + * Nearly the same as get_user_pages(), except that FOLL_TOUCH is not set, and + * FOLL_PIN is set. + * + * FOLL_PIN means that the pages must be released via put_user_page(). Please + * see Documentation/vm/pin_user_pages.rst for details. + * + * This is intended for Case 1 (DIO) in Documentation/vm/pin_user_pages.rst. It + * is NOT intended for Case 2 (RDMA: long-term pins). + */ +long pin_user_pages(unsigned long start, unsigned long nr_pages, + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas) +{ + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return -EINVAL; + + gup_flags |= FOLL_PIN; + return __gup_longterm_locked(current, current->mm, start, nr_pages, + pages, vmas, gup_flags); +} +EXPORT_SYMBOL(pin_user_pages); + +/** + * pin_longterm_pages() - pin user pages in memory for long-term use (RDMA, + * typically) + * + * Nearly the same as get_user_pages(), except that FOLL_PIN and FOLL_LONGTERM + * are set. See get_user_pages_fast() for documentation on the function + * arguments, because the arguments here are identical. + * + * FOLL_PIN means that the pages must be released via put_user_page(). Please + * see Documentation/vm/pin_user_pages.rst for further details. + * + * FOLL_LONGTERM means that the pages are being pinned for "long term" use, + * typically by a non-CPU device, and we cannot be sure that waiting for a + * pinned page to become unpin will be effective. + * + * This is intended for Case 2 (RDMA: long-term pins) in + * Documentation/vm/pin_user_pages.rst. + */ +long pin_longterm_pages(unsigned long start, unsigned long nr_pages, + unsigned int gup_flags, struct page **pages, + struct vm_area_struct **vmas) +{ + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return -EINVAL; + + gup_flags |= FOLL_PIN | FOLL_LONGTERM; + return __gup_longterm_locked(current, current->mm, start, nr_pages, + pages, vmas, gup_flags); +} +EXPORT_SYMBOL(pin_longterm_pages); From patchwork Tue Nov 12 00:06:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238021 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F0AB91864 for ; Tue, 12 Nov 2019 00:07:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C573F222CB for ; Tue, 12 Nov 2019 00:07:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="KzkkAZES" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727351AbfKLAHR (ORCPT ); Mon, 11 Nov 2019 19:07:17 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:16659 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727323AbfKLAHQ (ORCPT ); Mon, 11 Nov 2019 19:07:16 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:13 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:15 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Nov 2019 16:07:15 -0800 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:15 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:14 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:14 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 10/23] goldish_pipe: convert to pin_user_pages() and put_user_page() Date: Mon, 11 Nov 2019 16:06:47 -0800 Message-ID: <20191112000700.3455038-11-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517173; bh=1bdN1LXqKv0ya/hHPLN7inRIruwmJpRdnobIHlrvKRo=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=KzkkAZESmQXtGSFgWwG+sXWHcksTmOK88stfKoP8k1nw0eg1k1n7n7k3KMTtt0LyG G89SLPYAyfVse2C8PIFzEzOT6xIYX+TUEXtBuPp+eAwOy54UbelYtqyqYRfIRGokVS KCJTgNJMCoG5Dc2Ygi8THMLQHTfJujxgoYbVH600GHZ4enTwSOnsVCoyICAGe2fjvO /0L8YgDcIW+ZlGcSbHQM34bM/FhTobXA+62TTUAJfBP8JBJErh3UMcVSM7INQlIM3y qOQMbPuE1s239xB9nXq2bwxnUuRlqaYgrXILTdYi6kCr7loexReBQ0+AZOHiaWjxHU p5XXsz50ik9HQ== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 1. Call the new global pin_user_pages_fast(), from pin_goldfish_pages(). 2. As required by pin_user_pages(), release these pages via put_user_page(). In this case, do so via put_user_pages_dirty_lock(). That has the side effect of calling set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] Another side effect is that the release code is simplified because the page[] loop is now in gup.c instead of here, so just delete the local release_user_pages() entirely, and call put_user_pages_dirty_lock() directly, instead. [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Reviewed-by: Ira Weiny Signed-off-by: John Hubbard --- drivers/platform/goldfish/goldfish_pipe.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c index 7ed2a21a0bac..635a8bc1b480 100644 --- a/drivers/platform/goldfish/goldfish_pipe.c +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -274,7 +274,7 @@ static int pin_goldfish_pages(unsigned long first_page, *iter_last_page_size = last_page_size; } - ret = get_user_pages_fast(first_page, requested_pages, + ret = pin_user_pages_fast(first_page, requested_pages, !is_write ? FOLL_WRITE : 0, pages); if (ret <= 0) @@ -285,18 +285,6 @@ static int pin_goldfish_pages(unsigned long first_page, return ret; } -static void release_user_pages(struct page **pages, int pages_count, - int is_write, s32 consumed_size) -{ - int i; - - for (i = 0; i < pages_count; i++) { - if (!is_write && consumed_size > 0) - set_page_dirty(pages[i]); - put_page(pages[i]); - } -} - /* Populate the call parameters, merging adjacent pages together */ static void populate_rw_params(struct page **pages, int pages_count, @@ -372,7 +360,8 @@ static int transfer_max_buffers(struct goldfish_pipe *pipe, *consumed_size = pipe->command_buffer->rw_params.consumed_size; - release_user_pages(pipe->pages, pages_count, is_write, *consumed_size); + put_user_pages_dirty_lock(pipe->pages, pages_count, + !is_write && *consumed_size > 0); mutex_unlock(&pipe->lock); return 0; From patchwork Tue Nov 12 00:06:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238255 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 582F914E5 for ; Tue, 12 Nov 2019 00:09:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21FD920840 for ; Tue, 12 Nov 2019 00:09:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="a5xgZrZr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727511AbfKLAHY (ORCPT ); Mon, 11 Nov 2019 19:07:24 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:3329 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727482AbfKLAHW (ORCPT ); Mon, 11 Nov 2019 19:07:22 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:21 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:17 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:17 -0800 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:16 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:15 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:15 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 11/23] IB/{core,hw,umem}: set FOLL_PIN, FOLL_LONGTERM via pin_longterm_pages*() Date: Mon, 11 Nov 2019 16:06:48 -0800 Message-ID: <20191112000700.3455038-12-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517181; bh=5nX/THDsrOXdU0b+XUET79+1RnNMMrvnZjBYt5DvngE=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=a5xgZrZr5Ib7OOgqqc8Afi9jpUPyK56KbytbYrThxUv8xQEpN1Z7ds54HklxwiErC 2a+eH+pyET6Ra5wmbMV30IhV9k8m/4coaT9MWdeSfc0bua65zKIlk5fNkhm47pT5OU 3YhmDNhefK8KVEyQhIubU9/lEkKlTfAqsaoKPiuLwgPp5SCIYnJkWGWuto63+etHXF FPu9Nkq1mJwv5xk6jTOf9QRU2FhNTp9H5k/GdHw7uv2p0Duzf/AaiIdIlJgmhUmEsl aIsTSFlvuyEufThNWAB/0+w9bl69hWNYGCbCeKVrvvf4T6J5NYaL2l4MqMhUlzDh+a QeeMzl+55wD2g== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Convert infiniband to use the new wrapper calls, and stop explicitly setting FOLL_LONGTERM at the call sites. The new pin_longterm_*() calls replace get_user_pages*() calls, and set both FOLL_LONGTERM and a new FOLL_PIN flag. The FOLL_PIN flag requires that the caller must return the pages via put_user_page*() calls, but infiniband was already doing that as part of an earlier commit. Reviewed-by: Ira Weiny Signed-off-by: John Hubbard --- drivers/infiniband/core/umem.c | 10 ++++----- drivers/infiniband/core/umem_odp.c | 24 ++++++++++----------- drivers/infiniband/hw/hfi1/user_pages.c | 4 ++-- drivers/infiniband/hw/mthca/mthca_memfree.c | 3 +-- drivers/infiniband/hw/qib/qib_user_pages.c | 8 +++---- drivers/infiniband/hw/qib/qib_user_sdma.c | 2 +- drivers/infiniband/hw/usnic/usnic_uiom.c | 9 ++++---- drivers/infiniband/sw/siw/siw_mem.c | 5 ++--- 8 files changed, 31 insertions(+), 34 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 3d664a2539eb..7f03f72e6dce 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -271,11 +271,11 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, sg = umem->sg_head.sgl; while (npages) { - ret = get_user_pages_fast(cur_base, - min_t(unsigned long, npages, - PAGE_SIZE / - sizeof(struct page *)), - gup_flags | FOLL_LONGTERM, page_list); + ret = pin_longterm_pages_fast(cur_base, + min_t(unsigned long, npages, + PAGE_SIZE / + sizeof(struct page *)), + gup_flags, page_list); if (ret < 0) goto umem_release; diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index 163ff7ba92b7..b0ae039f884d 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -495,9 +495,8 @@ EXPORT_SYMBOL(ib_umem_odp_release); * The function returns -EFAULT if the DMA mapping operation fails. It returns * -EAGAIN if a concurrent invalidation prevents us from updating the page. * - * The page is released via put_user_page even if the operation failed. For - * on-demand pinning, the page is released whenever it isn't stored in the - * umem. + * The page is released via put_page even if the operation failed. For on-demand + * pinning, the page is released whenever it isn't stored in the umem. */ static int ib_umem_odp_map_dma_single_page( struct ib_umem_odp *umem_odp, @@ -542,7 +541,7 @@ static int ib_umem_odp_map_dma_single_page( } out: - put_user_page(page); + put_page(page); if (remove_existing_mapping) { ib_umem_notifier_start_account(umem_odp); @@ -639,13 +638,14 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt, /* * Note: this might result in redundent page getting. We can * avoid this by checking dma_list to be 0 before calling - * get_user_pages. However, this make the code much more - * complex (and doesn't gain us much performance in most use - * cases). + * get_user_pages. However, this makes the code much + * more complex (and doesn't gain us much performance in most + * use cases). */ npages = get_user_pages_remote(owning_process, owning_mm, - user_virt, gup_num_pages, - flags, local_page_list, NULL, NULL); + user_virt, gup_num_pages, + flags, local_page_list, NULL, + NULL); up_read(&owning_mm->mmap_sem); if (npages < 0) { @@ -665,7 +665,7 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt, ret = -EFAULT; break; } - put_user_page(local_page_list[j]); + put_page(local_page_list[j]); continue; } @@ -692,8 +692,8 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt, * ib_umem_odp_map_dma_single_page(). */ if (npages - (j + 1) > 0) - put_user_pages(&local_page_list[j+1], - npages - (j + 1)); + release_pages(&local_page_list[j+1], + npages - (j + 1)); break; } } diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c index 469acb961fbd..9b55b0a73e29 100644 --- a/drivers/infiniband/hw/hfi1/user_pages.c +++ b/drivers/infiniband/hw/hfi1/user_pages.c @@ -104,9 +104,9 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np bool writable, struct page **pages) { int ret; - unsigned int gup_flags = FOLL_LONGTERM | (writable ? FOLL_WRITE : 0); + unsigned int gup_flags = (writable ? FOLL_WRITE : 0); - ret = get_user_pages_fast(vaddr, npages, gup_flags, pages); + ret = pin_longterm_pages_fast(vaddr, npages, gup_flags, pages); if (ret < 0) return ret; diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c index edccfd6e178f..beec7e4b8a96 100644 --- a/drivers/infiniband/hw/mthca/mthca_memfree.c +++ b/drivers/infiniband/hw/mthca/mthca_memfree.c @@ -472,8 +472,7 @@ int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar, goto out; } - ret = get_user_pages_fast(uaddr & PAGE_MASK, 1, - FOLL_WRITE | FOLL_LONGTERM, pages); + ret = pin_longterm_pages_fast(uaddr & PAGE_MASK, 1, FOLL_WRITE, pages); if (ret < 0) goto out; diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c index 6bf764e41891..684a14e14d9b 100644 --- a/drivers/infiniband/hw/qib/qib_user_pages.c +++ b/drivers/infiniband/hw/qib/qib_user_pages.c @@ -108,10 +108,10 @@ int qib_get_user_pages(unsigned long start_page, size_t num_pages, down_read(¤t->mm->mmap_sem); for (got = 0; got < num_pages; got += ret) { - ret = get_user_pages(start_page + got * PAGE_SIZE, - num_pages - got, - FOLL_LONGTERM | FOLL_WRITE | FOLL_FORCE, - p + got, NULL); + ret = pin_longterm_pages(start_page + got * PAGE_SIZE, + num_pages - got, + FOLL_WRITE | FOLL_FORCE, + p + got, NULL); if (ret < 0) { up_read(¤t->mm->mmap_sem); goto bail_release; diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c index 05190edc2611..fd86a9d19370 100644 --- a/drivers/infiniband/hw/qib/qib_user_sdma.c +++ b/drivers/infiniband/hw/qib/qib_user_sdma.c @@ -670,7 +670,7 @@ static int qib_user_sdma_pin_pages(const struct qib_devdata *dd, else j = npages; - ret = get_user_pages_fast(addr, j, FOLL_LONGTERM, pages); + ret = pin_longterm_pages_fast(addr, j, 0, pages); if (ret != j) { i = 0; j = ret; diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index 62e6ffa9ad78..6b90ca1c3771 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -141,11 +141,10 @@ static int usnic_uiom_get_pages(unsigned long addr, size_t size, int writable, ret = 0; while (npages) { - ret = get_user_pages(cur_base, - min_t(unsigned long, npages, - PAGE_SIZE / sizeof(struct page *)), - gup_flags | FOLL_LONGTERM, - page_list, NULL); + ret = pin_longterm_pages(cur_base, + min_t(unsigned long, npages, + PAGE_SIZE / sizeof(struct page *)), + gup_flags, page_list, NULL); if (ret < 0) goto out; diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c index e99983f07663..20e663d7ada8 100644 --- a/drivers/infiniband/sw/siw/siw_mem.c +++ b/drivers/infiniband/sw/siw/siw_mem.c @@ -426,9 +426,8 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) while (nents) { struct page **plist = &umem->page_chunk[i].plist[got]; - rv = get_user_pages(first_page_va, nents, - foll_flags | FOLL_LONGTERM, - plist, NULL); + rv = pin_longterm_pages(first_page_va, nents, + foll_flags, plist, NULL); if (rv < 0) goto out_sem_up; From patchwork Tue Nov 12 00:06:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238281 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B76C716B1 for ; Tue, 12 Nov 2019 00:10:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96CE821872 for ; Tue, 12 Nov 2019 00:10:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="PqOu2gGr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727024AbfKLAJu (ORCPT ); Mon, 11 Nov 2019 19:09:50 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:16681 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727417AbfKLAHT (ORCPT ); Mon, 11 Nov 2019 19:07:19 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:16 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:18 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Nov 2019 16:07:18 -0800 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:18 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:16 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:16 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 12/23] mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote() Date: Mon, 11 Nov 2019 16:06:49 -0800 Message-ID: <20191112000700.3455038-13-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517176; bh=3Py2O4K3WxT2/yPBKlFkEQrJEl3zr7dYM5uV5CiR5XQ=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=PqOu2gGrt4yPc1T9tX6zhkH7invPzsZgO/C6ZqE5zQz2DIFQw9DLsdHGiEQsACOmr REvLimBqdAK3G9Lka7QSCUjGMiiCJ9Umq1kHatYlMcRQGoZ9t2mcKgFgxyTIgxFkFe KyvKAvPkOkGw1ZAWdb7VYga194WAjTUMv5r/TECnVFi0ryPvMt0BO6GMSf4RaS4B2+ HfkAZ3USwjZCq4qwGgr5t17jk5mnULpsYxHQBC/D4gBwrquycyRjvppfg2l8HjCZvp rezKt17AgS7ee8655DgxOQkn6ddMRB2xTS87e8KOEiBpRL0NLea8Fi7NHa9l5Gzz38 AMpQAKqOX5wUA== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Convert process_vm_access to use the new pin_user_pages_remote() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages. Also, release the pages via put_user_page*(). Also, rename "pages" to "pinned_pages", as this makes for easier reading of process_vm_rw_single_vec(). Reviewed-by: Jérôme Glisse Reviewed-by: Ira Weiny Signed-off-by: John Hubbard --- mm/process_vm_access.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 357aa7bef6c0..fd20ab675b85 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -42,12 +42,11 @@ static int process_vm_rw_pages(struct page **pages, if (copy > len) copy = len; - if (vm_write) { + if (vm_write) copied = copy_page_from_iter(page, offset, copy, iter); - set_page_dirty_lock(page); - } else { + else copied = copy_page_to_iter(page, offset, copy, iter); - } + len -= copied; if (copied < copy && iov_iter_count(iter)) return -EFAULT; @@ -96,7 +95,7 @@ static int process_vm_rw_single_vec(unsigned long addr, flags |= FOLL_WRITE; while (!rc && nr_pages && iov_iter_count(iter)) { - int pages = min(nr_pages, max_pages_per_loop); + int pinned_pages = min(nr_pages, max_pages_per_loop); int locked = 1; size_t bytes; @@ -106,14 +105,15 @@ static int process_vm_rw_single_vec(unsigned long addr, * current/current->mm */ down_read(&mm->mmap_sem); - pages = get_user_pages_remote(task, mm, pa, pages, flags, - process_pages, NULL, &locked); + pinned_pages = pin_user_pages_remote(task, mm, pa, pinned_pages, + flags, process_pages, + NULL, &locked); if (locked) up_read(&mm->mmap_sem); - if (pages <= 0) + if (pinned_pages <= 0) return -EFAULT; - bytes = pages * PAGE_SIZE - start_offset; + bytes = pinned_pages * PAGE_SIZE - start_offset; if (bytes > len) bytes = len; @@ -122,10 +122,12 @@ static int process_vm_rw_single_vec(unsigned long addr, vm_write); len -= bytes; start_offset = 0; - nr_pages -= pages; - pa += pages * PAGE_SIZE; - while (pages) - put_page(process_pages[--pages]); + nr_pages -= pinned_pages; + pa += pinned_pages * PAGE_SIZE; + + /* If vm_write is set, the pages need to be made dirty: */ + put_user_pages_dirty_lock(process_pages, pinned_pages, + vm_write); } return rc; From patchwork Tue Nov 12 00:06:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238239 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5D8A614E5 for ; Tue, 12 Nov 2019 00:09:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B8C821872 for ; Tue, 12 Nov 2019 00:09:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="YzsFSAxK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727516AbfKLAHZ (ORCPT ); Mon, 11 Nov 2019 19:07:25 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:16698 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727453AbfKLAHU (ORCPT ); Mon, 11 Nov 2019 19:07:20 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:18 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:19 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:19 -0800 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:19 +0000 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:18 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:17 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:17 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , "Mauro Carvalho Chehab" , Michael Ellerman , Michal Hocko , Mike Kravetz , "Paul Mackerras" , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard , "Daniel Vetter" Subject: [PATCH v3 13/23] drm/via: set FOLL_PIN via pin_user_pages_fast() Date: Mon, 11 Nov 2019 16:06:50 -0800 Message-ID: <20191112000700.3455038-14-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517178; bh=ky7gpstoQdJr5rtxFEQnjpS0lvKe5L6cg7jiu/68ipE=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=YzsFSAxKbG15u3QgSNio6pJKXjfnftsZ5SniRAeA+7yL72j635b+q/WwJzr4X0v4Y 152OHaQ+ouMz7eIqZEDyjshZMy6cYQHcnCJ6yINPjoIydTFEoVsXoROcrVfqFeHkJa Y2e/BikIKneTbza8bu80gnTIo3XTOaOB92IBGFt5SS9JD4R4bJRY/UENeTvU/6zVkG 1boGTp0KFofwlB897vtCSNuvDWx9gBItNi/ZF9cdKeE2Gl7eUfMr8K3Sk3nqrnoxya 6zZ8kGQIFSIFH/oKsI6LzKsOSK0eF0Ktgt7ib43mDF7NcxOlzRcqsYTY9K+KFjZmUi DeRyBAPXTj7wQ== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Convert drm/via to use the new pin_user_pages_fast() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages, and therefore for any code that calls put_user_page(). In partial anticipation of this work, the drm/via driver was already calling put_user_page() instead of put_page(). Therefore, in order to convert from the get_user_pages()/put_page() model, to the pin_user_pages()/put_user_page() model, the only change required is to change get_user_pages() to pin_user_pages(). Acked-by: Daniel Vetter Reviewed-by: Jérôme Glisse Reviewed-by: Ira Weiny Signed-off-by: John Hubbard --- drivers/gpu/drm/via/via_dmablit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/via/via_dmablit.c b/drivers/gpu/drm/via/via_dmablit.c index 3db000aacd26..37c5e572993a 100644 --- a/drivers/gpu/drm/via/via_dmablit.c +++ b/drivers/gpu/drm/via/via_dmablit.c @@ -239,7 +239,7 @@ via_lock_all_dma_pages(drm_via_sg_info_t *vsg, drm_via_dmablit_t *xfer) vsg->pages = vzalloc(array_size(sizeof(struct page *), vsg->num_pages)); if (NULL == vsg->pages) return -ENOMEM; - ret = get_user_pages_fast((unsigned long)xfer->mem_addr, + ret = pin_user_pages_fast((unsigned long)xfer->mem_addr, vsg->num_pages, vsg->direction == DMA_FROM_DEVICE ? FOLL_WRITE : 0, vsg->pages); From patchwork Tue Nov 12 00:06:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238035 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A17FB14E5 for ; Tue, 12 Nov 2019 00:07:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F260222D2 for ; Tue, 12 Nov 2019 00:07:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="dtrLh9SW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727503AbfKLAHX (ORCPT ); Mon, 11 Nov 2019 19:07:23 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10704 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726949AbfKLAHW (ORCPT ); Mon, 11 Nov 2019 19:07:22 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:23 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:20 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:20 -0800 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:20 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:19 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:18 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 14/23] fs/io_uring: set FOLL_PIN via pin_user_pages() Date: Mon, 11 Nov 2019 16:06:51 -0800 Message-ID: <20191112000700.3455038-15-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517243; bh=JGzVxjkq7RUQ8oMNLIEnYl2kvvauj6PckGww94CdhYA=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=dtrLh9SWLRdw6PX3vOEYVbDwP5rXYl+Z084f1/41lIx5jOckvj48bpZIb3QKiKvS8 EiUpJMH10AO0sZ3WIbPTzpRCzEmK7CwBwUTngL4bUg9ENPjwqA3LQxG7VJkrnsnZKn xt0RBUYD1lfBhCcLxZKjC2ZgHLuHAt4vUJr1H5DKsmGeTn5JRvpe5L0ToxTyELkqAp Sn56SxFS78D4kUkuucIgSnMczGsI7gGFSoTdRlMLriaEdgrOjUM+mJRGPdxeaIA0Tj vOlq1yc3ZS1Ui4kNjjddg7ITTuKySXmzU4DEFo3QcBBEQ5nOQNfWTtaxf/p1lt8uTG SzmwrtkLZlpEA== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Convert fs/io_uring to use the new pin_user_pages() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages, and therefore for any code that calls put_user_page(). In partial anticipation of this work, the io_uring code was already calling put_user_page() instead of put_page(). Therefore, in order to convert from the get_user_pages()/put_page() model, to the pin_user_pages()/put_user_page() model, the only change required here is to change get_user_pages() to pin_longterm_pages(). Reviewed-by: Ira Weiny Reviewed-by: Jens Axboe Signed-off-by: John Hubbard --- fs/io_uring.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index f9a38998f2fc..0f307f2c7cac 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3433,9 +3433,8 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, ret = 0; down_read(¤t->mm->mmap_sem); - pret = get_user_pages(ubuf, nr_pages, - FOLL_WRITE | FOLL_LONGTERM, - pages, vmas); + pret = pin_longterm_pages(ubuf, nr_pages, FOLL_WRITE, pages, + vmas); if (pret == nr_pages) { /* don't support file backed memory */ for (j = 0; j < nr_pages; j++) { From patchwork Tue Nov 12 00:06:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238215 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9127B14E5 for ; Tue, 12 Nov 2019 00:09:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6EE0621D7F for ; Tue, 12 Nov 2019 00:09:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="Daw1gXi5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727896AbfKLAJF (ORCPT ); Mon, 11 Nov 2019 19:09:05 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:3377 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727527AbfKLAH0 (ORCPT ); Mon, 11 Nov 2019 19:07:26 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:25 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:21 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Nov 2019 16:07:21 -0800 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:21 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:20 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:19 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 15/23] net/xdp: set FOLL_PIN via pin_user_pages() Date: Mon, 11 Nov 2019 16:06:52 -0800 Message-ID: <20191112000700.3455038-16-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517185; bh=7NW5FVByU2q47q8YXJg0DLnVCFYBzjS19tQtlG28KDY=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=Daw1gXi5Nf8jhwQGkFuKATjIjdGTo/8QHCXHZE7HOCQsxIKzJaEMCfUmt1gepoDlz wAtZERC/OIZdJ+dC7qyRHHNRHe+c8VRZ6WxtX0ujRzrLUzUNNhd/2aUReq75nVQOnB hXYlG0kMXNbnL0FAO1VMoSv0HZQiFBzWo/Le+8G03Vf47g41hmlrLcQOpTobmPcOfd 3gyGQm9Q39Wz3SpcrYOGhVOaHpFtHfuoItD2ZOM8vvYKso23c3EiSIlN3hYPQ0r19n XdosFXuIQ6dG3YNzHqIrFPxXBYW8pEAU+rzMaRN4Ou24/T3o3hVX/yxtTg/YPDbivh 8HR5xsqA3ACUQ== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Convert net/xdp to use the new pin_longterm_pages() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages. In partial anticipation of this work, the net/xdp code was already calling put_user_page() instead of put_page(). Therefore, in order to convert from the get_user_pages()/put_page() model, to the pin_user_pages()/put_user_page() model, the only change required here is to change get_user_pages() to pin_longterm_pages(). Reviewed-by: Ira Weiny Acked-by: Björn Töpel Signed-off-by: John Hubbard --- net/xdp/xdp_umem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 3049af269fbf..66c814863cfd 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -291,8 +291,8 @@ static int xdp_umem_pin_pages(struct xdp_umem *umem) return -ENOMEM; down_read(¤t->mm->mmap_sem); - npgs = get_user_pages(umem->address, umem->npgs, - gup_flags | FOLL_LONGTERM, &umem->pgs[0], NULL); + npgs = pin_longterm_pages(umem->address, umem->npgs, gup_flags, + &umem->pgs[0], NULL); up_read(¤t->mm->mmap_sem); if (npgs != umem->npgs) { From patchwork Tue Nov 12 00:06:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238237 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 402BF14E5 for ; Tue, 12 Nov 2019 00:09:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A17621872 for ; Tue, 12 Nov 2019 00:09:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="M2l68GlZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727593AbfKLAJF (ORCPT ); Mon, 11 Nov 2019 19:09:05 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:16736 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727497AbfKLAH0 (ORCPT ); Mon, 11 Nov 2019 19:07:26 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:20 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:22 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Nov 2019 16:07:22 -0800 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:22 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:21 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:21 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 16/23] mm/gup: track FOLL_PIN pages Date: Mon, 11 Nov 2019 16:06:53 -0800 Message-ID: <20191112000700.3455038-17-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517180; bh=dYDsBNoCc3j3xBsicl5hq4Ee4AWgl5sCKuYiruAHrxc=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=M2l68GlZ9tIDizsrkHmX0+ursgAdXLIpV7hz5cIywJAQQiCT2xsasfKUOi6L0NM2k OyHFbk547fCcgBYtF/ed1W6GZqddTKvvW0PcCitDxGl3Grj3m8XgsXrzx+s5CcLfGt KheQPIg2O7ieSielszOPk24j7W/l9wqHdJzwzCvVtl/O0qoSKf0KkxMC34EYmd37Aq W0HeiQBNspe+YT6lvjINxNnmInTDOLmH+ZvAnT0SLMC1wvnNozW+6dF60WakZIql2m jnWOeyn9i6VNFcpB18R2lYFT93VVTf0W+yFydT0p5tYBsE3VpXnz6jQjGBW0bITkWZ 9u3r4hhLDDIgQ== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Add tracking of pages that were pinned via FOLL_PIN. As mentioned in the FOLL_PIN documentation, callers who effectively set FOLL_PIN are required to ultimately free such pages via put_user_page(). The effect is similar to FOLL_GET, and may be thought of as "FOLL_GET for DIO and/or RDMA use". Pages that have been pinned via FOLL_PIN are identifiable via a new function call: bool page_dma_pinned(struct page *page); What to do in response to encountering such a page, is left to later patchsets. There is discussion about this in [1]. This also changes a BUG_ON(), to a WARN_ON(), in follow_page_mask(). Suggested-by: Jan Kara Suggested-by: Jérôme Glisse Signed-off-by: John Hubbard --- include/linux/mm.h | 75 ++++++++++++---- include/linux/mmzone.h | 2 + include/linux/page_ref.h | 10 +++ mm/gup.c | 190 +++++++++++++++++++++++++++++++++------ mm/huge_memory.c | 54 ++++++++++- mm/hugetlb.c | 39 +++++++- mm/vmstat.c | 2 + 7 files changed, 322 insertions(+), 50 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 11e0086d64a4..19b3fa68a4da 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1054,6 +1054,8 @@ static inline __must_check bool try_get_page(struct page *page) return true; } +__must_check bool user_page_ref_inc(struct page *page); + static inline void put_page(struct page *page) { page = compound_head(page); @@ -1071,31 +1073,70 @@ static inline void put_page(struct page *page) __put_page(page); } -/** - * put_user_page() - release a gup-pinned page - * @page: pointer to page to be released +/* + * GUP_PIN_COUNTING_BIAS, and the associated functions that use it, overload + * the page's refcount so that two separate items are tracked: the original page + * reference count, and also a new count of how many get_user_pages() calls were + * made against the page. ("gup-pinned" is another term for the latter). + * + * With this scheme, get_user_pages() becomes special: such pages are marked + * as distinct from normal pages. As such, the new put_user_page() call (and + * its variants) must be used in order to release gup-pinned pages. + * + * Choice of value: * - * Pages that were pinned via get_user_pages*() must be released via - * either put_user_page(), or one of the put_user_pages*() routines - * below. This is so that eventually, pages that are pinned via - * get_user_pages*() can be separately tracked and uniquely handled. In - * particular, interactions with RDMA and filesystems need special - * handling. + * By making GUP_PIN_COUNTING_BIAS a power of two, debugging of page reference + * counts with respect to get_user_pages() and put_user_page() becomes simpler, + * due to the fact that adding an even power of two to the page refcount has + * the effect of using only the upper N bits, for the code that counts up using + * the bias value. This means that the lower bits are left for the exclusive + * use of the original code that increments and decrements by one (or at least, + * by much smaller values than the bias value). * - * put_user_page() and put_page() are not interchangeable, despite this early - * implementation that makes them look the same. put_user_page() calls must - * be perfectly matched up with get_user_page() calls. + * Of course, once the lower bits overflow into the upper bits (and this is + * OK, because subtraction recovers the original values), then visual inspection + * no longer suffices to directly view the separate counts. However, for normal + * applications that don't have huge page reference counts, this won't be an + * issue. + * + * Locking: the lockless algorithm described in page_cache_get_speculative() + * and page_cache_gup_pin_speculative() provides safe operation for + * get_user_pages and page_mkclean and other calls that race to set up page + * table entries. */ -static inline void put_user_page(struct page *page) -{ - put_page(page); -} +#define GUP_PIN_COUNTING_BIAS (1UL << 10) +void put_user_page(struct page *page); void put_user_pages_dirty_lock(struct page **pages, unsigned long npages, bool make_dirty); - void put_user_pages(struct page **pages, unsigned long npages); +/** + * page_dma_pinned() - report if a page is pinned for DMA. + * + * This function checks if a page has been pinned via a call to + * pin_user_pages*() or pin_longterm_pages*(). + * + * The return value is partially fuzzy: false is not fuzzy, because it means + * "definitely not pinned for DMA", but true means "probably pinned for DMA, but + * possibly a false positive due to having at least GUP_PIN_COUNTING_BIAS worth + * of normal page references". + * + * False positives are OK, because: a) it's unlikely for a page to get that many + * refcounts, and b) all the callers of this routine are expected to be able to + * deal gracefully with a false positive. + * + * For more information, please see Documentation/vm/pin_user_pages.rst. + * + * @page: pointer to page to be queried. + * @Return: True, if it is likely that the page has been "dma-pinned". + * False, if the page is definitely not dma-pinned. + */ +static inline bool page_dma_pinned(struct page *page) +{ + return (page_ref_count(compound_head(page))) >= GUP_PIN_COUNTING_BIAS; +} + #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) #define SECTION_IN_PAGE_FLAGS #endif diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index bda20282746b..0485cba38d23 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -244,6 +244,8 @@ enum node_stat_item { NR_DIRTIED, /* page dirtyings since bootup */ NR_WRITTEN, /* page writings since bootup */ NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */ + NR_FOLL_PIN_REQUESTED, /* via: pin_user_page(), gup flag: FOLL_PIN */ + NR_FOLL_PIN_RETURNED, /* pages returned via put_user_page() */ NR_VM_NODE_STAT_ITEMS }; diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h index 14d14beb1f7f..b9cbe553d1e7 100644 --- a/include/linux/page_ref.h +++ b/include/linux/page_ref.h @@ -102,6 +102,16 @@ static inline void page_ref_sub(struct page *page, int nr) __page_ref_mod(page, -nr); } +static inline int page_ref_sub_return(struct page *page, int nr) +{ + int ret = atomic_sub_return(nr, &page->_refcount); + + if (page_ref_tracepoint_active(__tracepoint_page_ref_mod)) + __page_ref_mod(page, -nr); + + return ret; +} + static inline void page_ref_inc(struct page *page) { atomic_inc(&page->_refcount); diff --git a/mm/gup.c b/mm/gup.c index ea31810da828..fc164c2ee6b5 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -44,6 +44,95 @@ static inline struct page *try_get_compound_head(struct page *page, int refs) return head; } +#ifdef CONFIG_DEBUG_VM +static inline void __update_proc_vmstat(struct page *page, + enum node_stat_item item, int count) +{ + mod_node_page_state(page_pgdat(page), item, count); +} +#else +static inline void __update_proc_vmstat(struct page *page, + enum node_stat_item item, int count) +{ +} +#endif + +/** + * user_page_ref_inc() - mark a page as being used by get_user_pages(FOLL_PIN). + * + * @page: pointer to page to be marked + * @Return: true for success, false for failure + */ +__must_check bool user_page_ref_inc(struct page *page) +{ + page = try_get_compound_head(page, GUP_PIN_COUNTING_BIAS); + if (!page) + return false; + + __update_proc_vmstat(page, NR_FOLL_PIN_REQUESTED, 1); + return true; +} + +#ifdef CONFIG_DEV_PAGEMAP_OPS +static bool __put_devmap_managed_user_page(struct page *page) +{ + bool is_devmap = page_is_devmap_managed(page); + + if (is_devmap) { + int count = page_ref_sub_return(page, GUP_PIN_COUNTING_BIAS); + + __update_proc_vmstat(page, NR_FOLL_PIN_RETURNED, 1); + /* + * devmap page refcounts are 1-based, rather than 0-based: if + * refcount is 1, then the page is free and the refcount is + * stable because nobody holds a reference on the page. + */ + if (count == 1) + free_devmap_managed_page(page); + else if (!count) + __put_page(page); + } + + return is_devmap; +} +#else +static bool __put_devmap_managed_user_page(struct page *page) +{ + return false; +} +#endif /* CONFIG_DEV_PAGEMAP_OPS */ + +/** + * put_user_page() - release a gup-pinned page + * @page: pointer to page to be released + * + * Pages that were pinned via get_user_pages*() must be released via + * either put_user_page(), or one of the put_user_pages*() routines + * below. This is so that eventually, pages that are pinned via + * get_user_pages*() can be separately tracked and uniquely handled. In + * particular, interactions with RDMA and filesystems need special + * handling. + */ +void put_user_page(struct page *page) +{ + page = compound_head(page); + + /* + * For devmap managed pages we need to catch refcount transition from + * GUP_PIN_COUNTING_BIAS to 1, when refcount reach one it means the + * page is free and we need to inform the device driver through + * callback. See include/linux/memremap.h and HMM for details. + */ + if (__put_devmap_managed_user_page(page)) + return; + + if (page_ref_sub_and_test(page, GUP_PIN_COUNTING_BIAS)) + __put_page(page); + + __update_proc_vmstat(page, NR_FOLL_PIN_RETURNED, 1); +} +EXPORT_SYMBOL(put_user_page); + /** * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages * @pages: array of pages to be maybe marked dirty, and definitely released. @@ -230,10 +319,11 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, } page = vm_normal_page(vma, address, pte); - if (!page && pte_devmap(pte) && (flags & FOLL_GET)) { + if (!page && pte_devmap(pte) && (flags & (FOLL_GET | FOLL_PIN))) { /* - * Only return device mapping pages in the FOLL_GET case since - * they are only valid while holding the pgmap reference. + * Only return device mapping pages in the FOLL_GET or FOLL_PIN + * case since they are only valid while holding the pgmap + * reference. */ *pgmap = get_dev_pagemap(pte_pfn(pte), *pgmap); if (*pgmap) @@ -276,6 +366,11 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, page = ERR_PTR(-ENOMEM); goto out; } + } else if (flags & FOLL_PIN) { + if (unlikely(!user_page_ref_inc(page))) { + page = ERR_PTR(-ENOMEM); + goto out; + } } if (flags & FOLL_TOUCH) { if ((flags & FOLL_WRITE) && @@ -537,8 +632,8 @@ static struct page *follow_page_mask(struct vm_area_struct *vma, /* make this handle hugepd */ page = follow_huge_addr(mm, address, flags & FOLL_WRITE); if (!IS_ERR(page)) { - BUG_ON(flags & FOLL_GET); - return page; + WARN_ON_ONCE(flags & (FOLL_GET | FOLL_PIN)); + return NULL; } pgd = pgd_offset(mm, address); @@ -1830,13 +1925,17 @@ static inline pte_t gup_get_pte(pte_t *ptep) #endif /* CONFIG_GUP_GET_PTE_LOW_HIGH */ static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start, + unsigned int flags, struct page **pages) { while ((*nr) - nr_start) { struct page *page = pages[--(*nr)]; ClearPageReferenced(page); - put_page(page); + if (flags & FOLL_PIN) + put_user_page(page); + else + put_page(page); } } @@ -1869,7 +1968,7 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, pgmap = get_dev_pagemap(pte_pfn(pte), pgmap); if (unlikely(!pgmap)) { - undo_dev_pagemap(nr, nr_start, pages); + undo_dev_pagemap(nr, nr_start, flags, pages); goto pte_unmap; } } else if (pte_special(pte)) @@ -1878,9 +1977,15 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); - head = try_get_compound_head(page, 1); - if (!head) - goto pte_unmap; + if (flags & FOLL_PIN) { + head = page; + if (unlikely(!user_page_ref_inc(head))) + goto pte_unmap; + } else { + head = try_get_compound_head(page, 1); + if (!head) + goto pte_unmap; + } if (unlikely(pte_val(pte) != pte_val(*ptep))) { put_page(head); @@ -1934,12 +2039,20 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, pgmap = get_dev_pagemap(pfn, pgmap); if (unlikely(!pgmap)) { - undo_dev_pagemap(nr, nr_start, pages); + undo_dev_pagemap(nr, nr_start, flags, pages); return 0; } SetPageReferenced(page); pages[*nr] = page; - get_page(page); + + if (flags & FOLL_PIN) { + if (unlikely(!user_page_ref_inc(page))) { + undo_dev_pagemap(nr, nr_start, flags, pages); + return 0; + } + } else + get_page(page); + (*nr)++; pfn++; } while (addr += PAGE_SIZE, addr != end); @@ -1961,7 +2074,7 @@ static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, return 0; if (unlikely(pmd_val(orig) != pmd_val(*pmdp))) { - undo_dev_pagemap(nr, nr_start, pages); + undo_dev_pagemap(nr, nr_start, flags, pages); return 0; } return 1; @@ -1979,7 +2092,7 @@ static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, return 0; if (unlikely(pud_val(orig) != pud_val(*pudp))) { - undo_dev_pagemap(nr, nr_start, pages); + undo_dev_pagemap(nr, nr_start, flags, pages); return 0; } return 1; @@ -2063,9 +2176,16 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, page = head + ((addr & (sz-1)) >> PAGE_SHIFT); refs = __record_subpages(page, addr, end, pages, *nr); - head = try_get_compound_head(head, refs); - if (!head) - return 0; + if (flags & FOLL_PIN) { + head = page; + if (unlikely(!user_page_ref_inc(head))) + return 0; + head = page; + } else { + head = try_get_compound_head(head, refs); + if (!head) + return 0; + } if (unlikely(pte_val(pte) != pte_val(*ptep))) { put_compound_head(head, refs); @@ -2122,9 +2242,15 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, page = pmd_page(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); refs = __record_subpages(page, addr, end, pages, *nr); - head = try_get_compound_head(pmd_page(orig), refs); - if (!head) - return 0; + if (flags & FOLL_PIN) { + head = page; + if (unlikely(!user_page_ref_inc(head))) + return 0; + } else { + head = try_get_compound_head(pmd_page(orig), refs); + if (!head) + return 0; + } if (unlikely(pmd_val(orig) != pmd_val(*pmdp))) { put_compound_head(head, refs); @@ -2155,9 +2281,15 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, page = pud_page(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); refs = __record_subpages(page, addr, end, pages, *nr); - head = try_get_compound_head(pud_page(orig), refs); - if (!head) - return 0; + if (flags & FOLL_PIN) { + head = page; + if (unlikely(!user_page_ref_inc(head))) + return 0; + } else { + head = try_get_compound_head(pud_page(orig), refs); + if (!head) + return 0; + } if (unlikely(pud_val(orig) != pud_val(*pudp))) { put_compound_head(head, refs); @@ -2183,9 +2315,15 @@ static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr, page = pgd_page(orig) + ((addr & ~PGDIR_MASK) >> PAGE_SHIFT); refs = __record_subpages(page, addr, end, pages, *nr); - head = try_get_compound_head(pgd_page(orig), refs); - if (!head) - return 0; + if (flags & FOLL_PIN) { + head = page; + if (unlikely(!user_page_ref_inc(head))) + return 0; + } else { + head = try_get_compound_head(pgd_page(orig), refs); + if (!head) + return 0; + } if (unlikely(pgd_val(orig) != pgd_val(*pgdp))) { put_compound_head(head, refs); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 13cc93785006..4010c269e9e5 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -945,6 +945,11 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, */ WARN_ONCE(flags & FOLL_COW, "mm: In follow_devmap_pmd with FOLL_COW set"); + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == + (FOLL_PIN | FOLL_GET))) + return NULL; + if (flags & FOLL_WRITE && !pmd_write(*pmd)) return NULL; @@ -960,7 +965,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, * device mapped pages can only be returned if the * caller will manage the page reference count. */ - if (!(flags & FOLL_GET)) + if (!(flags & (FOLL_GET | FOLL_PIN))) return ERR_PTR(-EEXIST); pfn += (addr & ~PMD_MASK) >> PAGE_SHIFT; @@ -968,7 +973,18 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, if (!*pgmap) return ERR_PTR(-EFAULT); page = pfn_to_page(pfn); - get_page(page); + + if (flags & FOLL_GET) + get_page(page); + else if (flags & FOLL_PIN) { + /* + * user_page_ref_inc() is not actually expected to fail here + * because we hold the pmd lock so no one can unmap the pmd and + * free the page that it points to. + */ + if (unlikely(!user_page_ref_inc(page))) + page = ERR_PTR(-EFAULT); + } return page; } @@ -1088,6 +1104,11 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, if (flags & FOLL_WRITE && !pud_write(*pud)) return NULL; + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == + (FOLL_PIN | FOLL_GET))) + return NULL; + if (pud_present(*pud) && pud_devmap(*pud)) /* pass */; else @@ -1099,8 +1120,10 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, /* * device mapped pages can only be returned if the * caller will manage the page reference count. + * + * At least one of FOLL_GET | FOLL_PIN must be set, so assert that here: */ - if (!(flags & FOLL_GET)) + if (!(flags & (FOLL_GET | FOLL_PIN))) return ERR_PTR(-EEXIST); pfn += (addr & ~PUD_MASK) >> PAGE_SHIFT; @@ -1108,7 +1131,18 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, if (!*pgmap) return ERR_PTR(-EFAULT); page = pfn_to_page(pfn); - get_page(page); + + if (flags & FOLL_GET) + get_page(page); + else if (flags & FOLL_PIN) { + /* + * user_page_ref_inc() is not actually expected to fail here + * because we hold the pud lock so no one can unmap the pud and + * free the page that it points to. + */ + if (unlikely(!user_page_ref_inc(page))) + page = ERR_PTR(-EFAULT); + } return page; } @@ -1522,8 +1556,20 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, skip_mlock: page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; VM_BUG_ON_PAGE(!PageCompound(page) && !is_zone_device_page(page), page); + if (flags & FOLL_GET) get_page(page); + else if (flags & FOLL_PIN) { + /* + * user_page_ref_inc() is not actually expected to fail here + * because we hold the pmd lock so no one can unmap the pmd and + * free the page that it points to. + */ + if (unlikely(!user_page_ref_inc(page))) { + WARN_ON_ONCE(1); + page = NULL; + } + } out: return page; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index b45a95363a84..5ee80eea25e5 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4462,7 +4462,22 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, same_page: if (pages) { pages[i] = mem_map_offset(page, pfn_offset); - get_page(pages[i]); + + if (flags & FOLL_GET) + get_page(pages[i]); + else if (flags & FOLL_PIN) { + /* + * user_page_ref_inc() is not actually expected + * to fail here because we hold the ptl. + */ + if (unlikely(!user_page_ref_inc(pages[i]))) { + spin_unlock(ptl); + remainder = 0; + err = -ENOMEM; + WARN_ON_ONCE(1); + break; + } + } } if (vmas) @@ -5022,6 +5037,12 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, struct page *page = NULL; spinlock_t *ptl; pte_t pte; + + /* FOLL_GET and FOLL_PIN are mutually exclusive. */ + if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == + (FOLL_PIN | FOLL_GET))) + return NULL; + retry: ptl = pmd_lockptr(mm, pmd); spin_lock(ptl); @@ -5034,8 +5055,20 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, pte = huge_ptep_get((pte_t *)pmd); if (pte_present(pte)) { page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT); + if (flags & FOLL_GET) get_page(page); + else if (flags & FOLL_PIN) { + /* + * user_page_ref_inc() is not actually expected to fail + * here because we hold the ptl. + */ + if (unlikely(!user_page_ref_inc(page))) { + WARN_ON_ONCE(1); + page = NULL; + goto out; + } + } } else { if (is_hugetlb_entry_migration(pte)) { spin_unlock(ptl); @@ -5056,7 +5089,7 @@ struct page * __weak follow_huge_pud(struct mm_struct *mm, unsigned long address, pud_t *pud, int flags) { - if (flags & FOLL_GET) + if (flags & (FOLL_GET | FOLL_PIN)) return NULL; return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT); @@ -5065,7 +5098,7 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address, struct page * __weak follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags) { - if (flags & FOLL_GET) + if (flags & (FOLL_GET | FOLL_PIN)) return NULL; return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT); diff --git a/mm/vmstat.c b/mm/vmstat.c index a8222041bd44..fdad40ccde7b 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1167,6 +1167,8 @@ const char * const vmstat_text[] = { "nr_dirtied", "nr_written", "nr_kernel_misc_reclaimable", + "nr_foll_pin_requested", + "nr_foll_pin_returned", /* enum writeback_stat_item counters */ "nr_dirty_threshold", From patchwork Tue Nov 12 00:06:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238197 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3536E16B1 for ; Tue, 12 Nov 2019 00:09:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1354921D7F for ; Tue, 12 Nov 2019 00:09:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="j23aF6SR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727151AbfKLAIv (ORCPT ); Mon, 11 Nov 2019 19:08:51 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:3385 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727540AbfKLAH1 (ORCPT ); Mon, 11 Nov 2019 19:07:27 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:28 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:24 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 11 Nov 2019 16:07:24 -0800 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:23 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:22 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:22 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard , Hans Verkuil Subject: [PATCH v3 17/23] media/v4l2-core: pin_longterm_pages (FOLL_PIN) and put_user_page() conversion Date: Mon, 11 Nov 2019 16:06:54 -0800 Message-ID: <20191112000700.3455038-18-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517188; bh=GEhpFyTQIibXhYqN9YRdzJtS2txKyU2Kys/WSrzZyBk=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=j23aF6SRUen0YpYJHRc36hCPrcNFmaf1Sspp55AxN7SrAQXXqax6dRUmy0JvmNGRc u0MpdS14Jm9miNTgK1wzXZoX/13Y0bhlLKhQukrla4DOeLuT1Nr4mzyuJ7BVAnOTED LygPYrmrpoaDCaQGcXGHUTvJE30JgnWmJvVlF0ZaqTVe3HnBGGg86evwpinm/nBx7C RpSufllOzuEu+h3RY867f0PdpSIjlCRZHPg2cpFFtVIB1kage+mtuUAEYfgeoz+kPf iYZIsm8irI4/Q4QdeZUDeJCAg2aZN4dNQPnSF/5rDeBhJgXMx0L8QPm3tDbSBFCFEC tUgkh4YaE/z/Q== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 1. Change v4l2 from get_user_pages(FOLL_LONGTERM), to pin_longterm_pages(), which sets both FOLL_LONGTERM and FOLL_PIN. 2. Because all FOLL_PIN-acquired pages must be released via put_user_page(), also convert the put_page() call over to put_user_pages_dirty_lock(). Acked-by: Hans Verkuil Reviewed-by: Ira Weiny Cc: Mauro Carvalho Chehab Signed-off-by: John Hubbard --- drivers/media/v4l2-core/videobuf-dma-sg.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c index 28262190c3ab..9b9c5b37bf59 100644 --- a/drivers/media/v4l2-core/videobuf-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf-dma-sg.c @@ -183,12 +183,12 @@ static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma, dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n", data, size, dma->nr_pages); - err = get_user_pages(data & PAGE_MASK, dma->nr_pages, - flags | FOLL_LONGTERM, dma->pages, NULL); + err = pin_longterm_pages(data & PAGE_MASK, dma->nr_pages, + flags, dma->pages, NULL); if (err != dma->nr_pages) { dma->nr_pages = (err >= 0) ? err : 0; - dprintk(1, "get_user_pages: err=%d [%d]\n", err, + dprintk(1, "pin_longterm_pages: err=%d [%d]\n", err, dma->nr_pages); return err < 0 ? err : -EINVAL; } @@ -349,11 +349,8 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma) BUG_ON(dma->sglen); if (dma->pages) { - for (i = 0; i < dma->nr_pages; i++) { - if (dma->direction == DMA_FROM_DEVICE) - set_page_dirty_lock(dma->pages[i]); - put_page(dma->pages[i]); - } + put_user_pages_dirty_lock(dma->pages, dma->nr_pages, + dma->direction == DMA_FROM_DEVICE); kfree(dma->pages); dma->pages = NULL; } From patchwork Tue Nov 12 00:06:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238177 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 81C561864 for ; Tue, 12 Nov 2019 00:08:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EAE82184C for ; Tue, 12 Nov 2019 00:08:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="OOy4osFx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727790AbfKLAIh (ORCPT ); Mon, 11 Nov 2019 19:08:37 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:16770 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727539AbfKLAH1 (ORCPT ); Mon, 11 Nov 2019 19:07:27 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:23 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:25 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:25 -0800 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:24 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:23 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:23 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 18/23] vfio, mm: pin_longterm_pages (FOLL_PIN) and put_user_page() conversion Date: Mon, 11 Nov 2019 16:06:55 -0800 Message-ID: <20191112000700.3455038-19-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517183; bh=sSwCrqRKuW3/2RqWIzTidmab8smfkfN0es5ZTEERORQ=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=OOy4osFxRkHKhA4WgKXA5YhAniGLgnKkjxLIGE/ThvfX2DPQ68rl1TsLA9SZKnLVn dYYRm0QhBsaxq6ZHWmxSUwrNxOdd5Uyvb9KY+cvPN+kIh4WUWvxM/2f8kdLFhfLOzd sWevWhJFRkTu6vo+N0WxrYIOePZqIWcSyYJLSG9lwE5m0RgdK+/gdZXtsKPQQYnMWf xuhkwC8xNeb8u+BqAdzbH6Ylg8hYBWh5afDxUQfn7DyEWsylkTKvwQHs+WSfP4IPH1 58EeEb3okxK1KQAuYGIG7WJdZ33PHrGTE5RJvv/ycocsc+rQoqaJsyFcHJdnqX/pZX cyNKl7RGcRWQg== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 1. Change vfio from get_user_pages(FOLL_LONGTERM), to pin_longterm_pages(), which sets both FOLL_LONGTERM and FOLL_PIN. 2. Because all FOLL_PIN-acquired pages must be released via put_user_page(), also convert the put_page() call over to put_user_pages(). Note that this effectively changes the code's behavior in vfio_iommu_type1.c: put_pfn(): it now ultimately calls set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Cc: Alex Williamson Signed-off-by: John Hubbard --- drivers/vfio/vfio_iommu_type1.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 017689b7c32b..07bec0bdd316 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -327,9 +327,8 @@ static int put_pfn(unsigned long pfn, int prot) { if (!is_invalid_reserved_pfn(pfn)) { struct page *page = pfn_to_page(pfn); - if (prot & IOMMU_WRITE) - SetPageDirty(page); - put_page(page); + + put_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE); return 1; } return 0; @@ -348,8 +347,8 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, flags |= FOLL_WRITE; down_read(&mm->mmap_sem); - ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, - page, vmas, NULL); + ret = pin_longterm_pages_remote(NULL, mm, vaddr, 1, flags, page, vmas, + NULL); /* * The lifetime of a vaddr_get_pfn() page pin is * userspace-controlled. In the fs-dax case this could @@ -359,7 +358,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, */ if (ret > 0 && vma_is_fsdax(vmas[0])) { ret = -EOPNOTSUPP; - put_page(page[0]); + put_user_page(page[0]); } up_read(&mm->mmap_sem); From patchwork Tue Nov 12 00:06:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238073 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7382D1864 for ; Tue, 12 Nov 2019 00:07:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 51E3A222BD for ; Tue, 12 Nov 2019 00:07:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="kyMiML3+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727690AbfKLAHe (ORCPT ); Mon, 11 Nov 2019 19:07:34 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10813 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727675AbfKLAHd (ORCPT ); Mon, 11 Nov 2019 19:07:33 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:28 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:25 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:25 -0800 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:25 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:24 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:24 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 19/23] powerpc: book3s64: convert to pin_longterm_pages() and put_user_page() Date: Mon, 11 Nov 2019 16:06:56 -0800 Message-ID: <20191112000700.3455038-20-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517248; bh=jP0+G7EUrJzRbss/H6wqbMhvj/DAmG+WrBPGAFIWqJ8=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=kyMiML3+GMLGq0Jv8bzwxVi25OB/SoujLSswefLksQp3ZYNqPbwpIUlskN/5gXMJo 26zMPqilhOk76CMwC3yRdMDpAzKIXkR0MEZJVdSMBwH38lXkHGYuQNlpuu/zKcaG9V ZZ5dx5Uf/LSacxxcsBDJQcJh5HzLRrF5DoR8v3ofQxvmJtGshRKxXs2+NLPnf1hh1C nSOTCA5dYrBdyoZTK2x/8i2jFIC6tjMGwEeGYeRaD0BpdcEpWAE/3p1ssCsEJFlDxU GgshMWpoo5oW+vfQNOaVL4vvpLAP6wqv2Utz57IJTsBvBpV+JgLGtYR13mWIjoDhUP n604LsOZc9T0A== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 1. Convert from get_user_pages(FOLL_LONGTERM) to pin_longterm_pages(). 2. As required by pin_user_pages(), release these pages via put_user_page(). In this case, do so via put_user_pages_dirty_lock(). That has the side effect of calling set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] 3. Release each page in mem->hpages[] (instead of mem->hpas[]), because that is the array that pin_longterm_pages() filled in. This is more accurate and should be a little safer from a maintenance point of view. [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Signed-off-by: John Hubbard --- arch/powerpc/mm/book3s64/iommu_api.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c index 56cc84520577..69d79cb50d47 100644 --- a/arch/powerpc/mm/book3s64/iommu_api.c +++ b/arch/powerpc/mm/book3s64/iommu_api.c @@ -103,9 +103,8 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, for (entry = 0; entry < entries; entry += chunk) { unsigned long n = min(entries - entry, chunk); - ret = get_user_pages(ua + (entry << PAGE_SHIFT), n, - FOLL_WRITE | FOLL_LONGTERM, - mem->hpages + entry, NULL); + ret = pin_longterm_pages(ua + (entry << PAGE_SHIFT), n, + FOLL_WRITE, mem->hpages + entry, NULL); if (ret == n) { pinned += n; continue; @@ -167,9 +166,8 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, return 0; free_exit: - /* free the reference taken */ - for (i = 0; i < pinned; i++) - put_page(mem->hpages[i]); + /* free the references taken */ + put_user_pages(mem->hpages, pinned); vfree(mem->hpas); kfree(mem); @@ -212,10 +210,9 @@ static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem) if (!page) continue; - if (mem->hpas[i] & MM_IOMMU_TABLE_GROUP_PAGE_DIRTY) - SetPageDirty(page); + put_user_pages_dirty_lock(&mem->hpages[i], 1, + MM_IOMMU_TABLE_GROUP_PAGE_DIRTY); - put_page(page); mem->hpas[i] = 0; } } From patchwork Tue Nov 12 00:06:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238153 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 878CD14E5 for ; Tue, 12 Nov 2019 00:08:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 647D92196E for ; Tue, 12 Nov 2019 00:08:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="IfvI1TWt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727629AbfKLAIU (ORCPT ); Mon, 11 Nov 2019 19:08:20 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:3406 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727615AbfKLAH3 (ORCPT ); Mon, 11 Nov 2019 19:07:29 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:06:31 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:27 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:27 -0800 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:27 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:25 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:25 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 20/23] mm/gup_benchmark: use proper FOLL_WRITE flags instead of hard-coding "1" Date: Mon, 11 Nov 2019 16:06:57 -0800 Message-ID: <20191112000700.3455038-21-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517191; bh=7Vmsb+9KRgkgzRB+pY1tHWrSRQ+BM3AUrdVPH7GeYFc=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=IfvI1TWtyCjO8OKOwI3I6WbabrJYVA+N4Jz98QsvLpsrZ643xabZCJXPOx4MydE4D MuardO1IggwR2l+GAUtDMBIuT2QOyTWvgpRG4ViJuMFVzCUX53ZdppPYW1H/Wspg8t VCIWUAprOaL0MyjTiTLKKRdu4OipTnaSfDsI/FFYPSSeRnJkVWnzsv3+cCFITtYgbj CFdOqvnxVkrMp6RVFgPSm7x9J7q51Uzf0X0TPdZs+ckD9YPS/mFkdt/Kq0llzdav8t oMqra+Yu2pIf6BBwyRsPl4kqozyu6pF5TLHPmoUp9DxVy7iKslb3X7AuObyLgJltZO R+CroqZ5r/Shg== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Fix the gup benchmark flags to use the symbolic FOLL_WRITE, instead of a hard-coded "1" value. Also, clean up the filtering of gup flags a little, by just doing it once before issuing any of the get_user_pages*() calls. This makes it harder to overlook, instead of having little "gup_flags & 1" phrases in the function calls. Signed-off-by: John Hubbard --- mm/gup_benchmark.c | 9 ++++++--- tools/testing/selftests/vm/gup_benchmark.c | 6 +++++- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c index 7dd602d7f8db..7fc44d25eca7 100644 --- a/mm/gup_benchmark.c +++ b/mm/gup_benchmark.c @@ -48,18 +48,21 @@ static int __gup_benchmark_ioctl(unsigned int cmd, nr = (next - addr) / PAGE_SIZE; } + /* Filter out most gup flags: only allow a tiny subset here: */ + gup->flags &= FOLL_WRITE; + switch (cmd) { case GUP_FAST_BENCHMARK: - nr = get_user_pages_fast(addr, nr, gup->flags & 1, + nr = get_user_pages_fast(addr, nr, gup->flags, pages + i); break; case GUP_LONGTERM_BENCHMARK: nr = get_user_pages(addr, nr, - (gup->flags & 1) | FOLL_LONGTERM, + gup->flags | FOLL_LONGTERM, pages + i, NULL); break; case GUP_BENCHMARK: - nr = get_user_pages(addr, nr, gup->flags & 1, pages + i, + nr = get_user_pages(addr, nr, gup->flags, pages + i, NULL); break; default: diff --git a/tools/testing/selftests/vm/gup_benchmark.c b/tools/testing/selftests/vm/gup_benchmark.c index 485cf06ef013..389327e9b30a 100644 --- a/tools/testing/selftests/vm/gup_benchmark.c +++ b/tools/testing/selftests/vm/gup_benchmark.c @@ -18,6 +18,9 @@ #define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) +/* Just the flags we need, copied from mm.h: */ +#define FOLL_WRITE 0x01 /* check pte is writable */ + struct gup_benchmark { __u64 get_delta_usec; __u64 put_delta_usec; @@ -85,7 +88,8 @@ int main(int argc, char **argv) } gup.nr_pages_per_call = nr_pages; - gup.flags = write; + if (write) + gup.flags |= FOLL_WRITE; fd = open("/sys/kernel/debug/gup_benchmark", O_RDWR); if (fd == -1) From patchwork Tue Nov 12 00:06:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238127 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7F3CD16B1 for ; Tue, 12 Nov 2019 00:08:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53E34222BD for ; Tue, 12 Nov 2019 00:08:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="INNX4lb1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727641AbfKLAHb (ORCPT ); Mon, 11 Nov 2019 19:07:31 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10782 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727625AbfKLAHb (ORCPT ); Mon, 11 Nov 2019 19:07:31 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:31 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:28 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:28 -0800 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:27 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:27 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:26 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 21/23] mm/gup_benchmark: support pin_user_pages() and related calls Date: Mon, 11 Nov 2019 16:06:58 -0800 Message-ID: <20191112000700.3455038-22-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517251; bh=qDCGllxYSTERl727bBBMP3MdnPP+9frqWZ2/7CRJeGs=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=INNX4lb1n2kX1v/P9PM7wBHYChSdAomLQDogDbvbn82CeqEinhjAwB1rCxnCP79bt zREEFUMmQJCxmeEBySUGdu/xCEDT0HFsAI0lVm2mu4UVM5uwY4o1GHCLYEIops1Obf FlzPaA6vDkMI3yLspyfIQgVAT4OrKXuKScb28X1Nqyc5NdmMoKxG/PQkR2iKVQv+Aw +SC0FLAusBn+ViWOOqzj/2euAMwTny9EdpRQHffb0IWVB4oARQzUo63stjwjIWqDd5 SaqJJMBgrnY5U/MFSmt1wGulCyueGHwHz28ppbvOY3QsF40pmJd1EN/QKj72wd6aR7 LmrU8E9OoDYnA== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Up until now, gup_benchmark supported testing of the following kernel functions: * get_user_pages(): via the '-U' command line option * get_user_pages_longterm(): via the '-L' command line option * get_user_pages_fast(): as the default (no options required) Add test coverage for the new corresponding pin_*() functions: * pin_user_pages(): via the '-c' command line option * pin_longterm_pages(): via the '-b' command line option * pin_user_pages_fast(): via the '-a' command line option Also, add an option for clarity: '-u' for what is now (still) the default choice: get_user_pages_fast(). Also, for the three commands that set FOLL_PIN, verify that the pages really are dma-pinned, via the new is_dma_pinned() routine. Those commands are: PIN_FAST_BENCHMARK : calls pin_user_pages_fast() PIN_LONGTERM_BENCHMARK : calls pin_longterm_pages() PIN_BENCHMARK : calls pin_user_pages() In between the calls to pin_*() and put_user_pages(), check each page: if page_dma_pinned() returns false, then WARN and return. Do this outside of the benchmark timestamps, so that it doesn't affect reported times. Signed-off-by: John Hubbard --- mm/gup_benchmark.c | 73 ++++++++++++++++++++-- tools/testing/selftests/vm/gup_benchmark.c | 23 ++++++- 2 files changed, 90 insertions(+), 6 deletions(-) diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c index 7fc44d25eca7..8f980d91dbf5 100644 --- a/mm/gup_benchmark.c +++ b/mm/gup_benchmark.c @@ -8,6 +8,9 @@ #define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark) #define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) +#define PIN_FAST_BENCHMARK _IOWR('g', 4, struct gup_benchmark) +#define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_benchmark) +#define PIN_BENCHMARK _IOWR('g', 6, struct gup_benchmark) struct gup_benchmark { __u64 get_delta_usec; @@ -19,6 +22,44 @@ struct gup_benchmark { __u64 expansion[10]; /* For future use */ }; +static void put_back_pages(int cmd, struct page **pages, unsigned long nr_pages) +{ + int i; + + switch (cmd) { + case GUP_FAST_BENCHMARK: + case GUP_LONGTERM_BENCHMARK: + case GUP_BENCHMARK: + for (i = 0; i < nr_pages; i++) + put_page(pages[i]); + break; + + case PIN_FAST_BENCHMARK: + case PIN_LONGTERM_BENCHMARK: + case PIN_BENCHMARK: + put_user_pages(pages, nr_pages); + break; + } +} + +static void verify_dma_pinned(int cmd, struct page **pages, + unsigned long nr_pages) +{ + int i; + + switch (cmd) { + case PIN_FAST_BENCHMARK: + case PIN_LONGTERM_BENCHMARK: + case PIN_BENCHMARK: + for (i = 0; i < nr_pages; i++) { + if (WARN(!page_dma_pinned(pages[i]), + "pages[%d] is NOT dma-pinned\n", i)) + break; + } + break; + } +} + static int __gup_benchmark_ioctl(unsigned int cmd, struct gup_benchmark *gup) { @@ -65,6 +106,18 @@ static int __gup_benchmark_ioctl(unsigned int cmd, nr = get_user_pages(addr, nr, gup->flags, pages + i, NULL); break; + case PIN_FAST_BENCHMARK: + nr = pin_user_pages_fast(addr, nr, gup->flags, + pages + i); + break; + case PIN_LONGTERM_BENCHMARK: + nr = pin_longterm_pages(addr, nr, gup->flags, pages + i, + NULL); + break; + case PIN_BENCHMARK: + nr = pin_user_pages(addr, nr, gup->flags, pages + i, + NULL); + break; default: return -1; } @@ -75,15 +128,22 @@ static int __gup_benchmark_ioctl(unsigned int cmd, } end_time = ktime_get(); + /* Shifting the meaning of nr_pages: now it is actual number pinned: */ + nr_pages = i; + gup->get_delta_usec = ktime_us_delta(end_time, start_time); gup->size = addr - gup->addr; + /* + * Take an un-benchmark-timed moment to verify DMA pinned + * state: print a warning if any non-dma-pinned pages are found: + */ + verify_dma_pinned(cmd, pages, nr_pages); + start_time = ktime_get(); - for (i = 0; i < nr_pages; i++) { - if (!pages[i]) - break; - put_page(pages[i]); - } + + put_back_pages(cmd, pages, nr_pages); + end_time = ktime_get(); gup->put_delta_usec = ktime_us_delta(end_time, start_time); @@ -101,6 +161,9 @@ static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd, case GUP_FAST_BENCHMARK: case GUP_LONGTERM_BENCHMARK: case GUP_BENCHMARK: + case PIN_FAST_BENCHMARK: + case PIN_LONGTERM_BENCHMARK: + case PIN_BENCHMARK: break; default: return -EINVAL; diff --git a/tools/testing/selftests/vm/gup_benchmark.c b/tools/testing/selftests/vm/gup_benchmark.c index 389327e9b30a..03928e47a86f 100644 --- a/tools/testing/selftests/vm/gup_benchmark.c +++ b/tools/testing/selftests/vm/gup_benchmark.c @@ -18,6 +18,15 @@ #define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) +/* + * Similar to above, but use FOLL_PIN instead of FOLL_GET. This is done + * by calling pin_user_pages_fast(), pin_longterm_pages(), and pin_user_pages(), + * respectively. + */ +#define PIN_FAST_BENCHMARK _IOWR('g', 4, struct gup_benchmark) +#define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_benchmark) +#define PIN_BENCHMARK _IOWR('g', 6, struct gup_benchmark) + /* Just the flags we need, copied from mm.h: */ #define FOLL_WRITE 0x01 /* check pte is writable */ @@ -40,8 +49,17 @@ int main(int argc, char **argv) char *file = "/dev/zero"; char *p; - while ((opt = getopt(argc, argv, "m:r:n:f:tTLUwSH")) != -1) { + while ((opt = getopt(argc, argv, "m:r:n:f:abctTLUuwSH")) != -1) { switch (opt) { + case 'a': + cmd = PIN_FAST_BENCHMARK; + break; + case 'b': + cmd = PIN_LONGTERM_BENCHMARK; + break; + case 'c': + cmd = PIN_BENCHMARK; + break; case 'm': size = atoi(optarg) * MB; break; @@ -63,6 +81,9 @@ int main(int argc, char **argv) case 'U': cmd = GUP_BENCHMARK; break; + case 'u': + cmd = GUP_FAST_BENCHMARK; + break; case 'w': write = 1; break; From patchwork Tue Nov 12 00:06:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238111 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D9E731920 for ; Tue, 12 Nov 2019 00:07:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8D1721E6F for ; Tue, 12 Nov 2019 00:07:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="Y02O+zm4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727683AbfKLAHs (ORCPT ); Mon, 11 Nov 2019 19:07:48 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10794 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727632AbfKLAHc (ORCPT ); Mon, 11 Nov 2019 19:07:32 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:32 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:29 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:29 -0800 Received: from HQMAIL107.nvidia.com (172.20.187.13) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:28 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:27 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:27 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 22/23] selftests/vm: run_vmtests: invoke gup_benchmark with basic FOLL_PIN coverage Date: Mon, 11 Nov 2019 16:06:59 -0800 Message-ID: <20191112000700.3455038-23-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517252; bh=xFb3SiLgCLKE3iiV7irzvOfCSAuS+AWjP3FT0BNaO3M=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=Y02O+zm41OtyFNsGjNycWuJAr67vxLxYcKkoymytbQptL0pJpNquIFtGtQxVGgjYi 6OplSmzWMi9MtpWyuey/r7bm3Ita5M1Yicz9xrz8WIHcRAfxADwp8wDMEkaNfBfHB7 TsxAeXqTTlUTi5f5c6ttks8pqWUeydYApff24tF22A5/4E3tXOHFbOyMois1MUdG6L ZVdGteudEW9Voaebi1PmqXqytVqMM9rY9d18kW+4HDfMGqxOTHcC7DRx8C2+qLLz1K FRi1I11rc4EM+xWMM5OiD//3jcIM0jl4AtlVKkVNt9E2Nk1GRMg+OyZDNOa8054Kyh vC7flmzVSQjjQ== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org It's good to have basic unit test coverage of the new FOLL_PIN behavior. Fortunately, the gup_benchmark unit test is extremely fast (a few milliseconds), so adding it the the run_vmtests suite is going to cause no noticeable change in running time. So, add two new invocations to run_vmtests: 1) Run gup_benchmark with normal get_user_pages(). 2) Run gup_benchmark with pin_user_pages(). This is much like the first call, except that it sets FOLL_PIN. Running these two in quick succession also provide a visual comparison of the running times, which is convenient. The new invocations are fairly early in the run_vmtests script, because with test suites, it's usually preferable to put the shorter, faster tests first, all other things being equal. Signed-off-by: John Hubbard --- tools/testing/selftests/vm/run_vmtests | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests index 951c507a27f7..93e8dc9a7cad 100755 --- a/tools/testing/selftests/vm/run_vmtests +++ b/tools/testing/selftests/vm/run_vmtests @@ -104,6 +104,28 @@ echo "NOTE: The above hugetlb tests provide minimal coverage. Use" echo " https://github.com/libhugetlbfs/libhugetlbfs.git for" echo " hugetlb regression testing." +echo "--------------------------------------------" +echo "running 'gup_benchmark -U' (normal/slow gup)" +echo "--------------------------------------------" +./gup_benchmark -U +if [ $? -ne 0 ]; then + echo "[FAIL]" + exitcode=1 +else + echo "[PASS]" +fi + +echo "------------------------------------------" +echo "running gup_benchmark -c (pin_user_pages)" +echo "------------------------------------------" +./gup_benchmark -c +if [ $? -ne 0 ]; then + echo "[FAIL]" + exitcode=1 +else + echo "[PASS]" +fi + echo "-------------------" echo "running userfaultfd" echo "-------------------" From patchwork Tue Nov 12 00:07:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11238131 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 13AA814E5 for ; Tue, 12 Nov 2019 00:08:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC929222CF for ; Tue, 12 Nov 2019 00:08:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="jeDFucw7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726912AbfKLAIE (ORCPT ); Mon, 11 Nov 2019 19:08:04 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:10792 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727631AbfKLAHb (ORCPT ); Mon, 11 Nov 2019 19:07:31 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 11 Nov 2019 16:07:33 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 11 Nov 2019 16:07:30 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 11 Nov 2019 16:07:30 -0800 Received: from HQMAIL107.nvidia.com (172.20.187.13) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 12 Nov 2019 00:07:30 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 12 Nov 2019 00:07:29 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 11 Nov 2019 16:07:29 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v3 23/23] mm/gup: remove support for gup(FOLL_LONGTERM) Date: Mon, 11 Nov 2019 16:07:00 -0800 Message-ID: <20191112000700.3455038-24-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191112000700.3455038-1-jhubbard@nvidia.com> References: <20191112000700.3455038-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1573517253; bh=cQGm03MwEI364eqhkDgW3lkBD2mDh5xmPmbbGUpAUxU=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=jeDFucw7tE0NfME1gtSntL7jl6FwAVKx401Zg0zd1OkOK23btFnhhwRkX1BypOId8 tB5L/HA86k7OcI07xiKO7SPq60A52WvJh6+uA0reTiW0Z5JqnjbNT8xfKH/mHa0AAf LXGFigUduDHPhfFDSdZFC243oMyts/7+rCWm2Jy33t/ZP00CwXdKXT72ELCCro7Ypj RelyojEcjFUpR+VNp3Kz50mWDTbe3Hqv0UhXwYhoLmNdXakM0Dw9hV3hWsEAA2x0LI p1qiFqadYG8i1oiRlkGsryI6OZveEzbEGW+7+g6ht6r3kDox/sRMIxnR+qCRLVVO1J rLJMc31P/tZAA== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Now that all other kernel callers of get_user_pages(FOLL_LONGTERM) have been converted to pin_longterm_pages(), lock it down: 1) Add an assertion to get_user_pages(), preventing callers from passing FOLL_LONGTERM (in addition to the existing assertion that prevents FOLL_PIN). 2) Remove the associated GUP_LONGTERM_BENCHMARK test. Signed-off-by: John Hubbard --- mm/gup.c | 8 ++++---- mm/gup_benchmark.c | 9 +-------- tools/testing/selftests/vm/gup_benchmark.c | 7 ++----- 3 files changed, 7 insertions(+), 17 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index fc164c2ee6b5..db73ba216dff 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1743,11 +1743,11 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, struct vm_area_struct **vmas) { /* - * FOLL_PIN must only be set internally by the pin_user_page*() and - * pin_longterm_*() APIs, never directly by the caller, so enforce that - * with an assertion: + * FOLL_PIN and FOLL_LONGTERM must only be set internally by the + * pin_user_page*() and pin_longterm_*() APIs, never directly by the + * caller, so enforce that with an assertion: */ - if (WARN_ON_ONCE(gup_flags & FOLL_PIN)) + if (WARN_ON_ONCE(gup_flags & (FOLL_PIN | FOLL_LONGTERM))) return -EINVAL; return __gup_longterm_locked(current, current->mm, start, nr_pages, diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c index 8f980d91dbf5..679f0e6a0adb 100644 --- a/mm/gup_benchmark.c +++ b/mm/gup_benchmark.c @@ -6,7 +6,7 @@ #include #define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark) -#define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) +/* Command 2 has been deleted. */ #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) #define PIN_FAST_BENCHMARK _IOWR('g', 4, struct gup_benchmark) #define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_benchmark) @@ -28,7 +28,6 @@ static void put_back_pages(int cmd, struct page **pages, unsigned long nr_pages) switch (cmd) { case GUP_FAST_BENCHMARK: - case GUP_LONGTERM_BENCHMARK: case GUP_BENCHMARK: for (i = 0; i < nr_pages; i++) put_page(pages[i]); @@ -97,11 +96,6 @@ static int __gup_benchmark_ioctl(unsigned int cmd, nr = get_user_pages_fast(addr, nr, gup->flags, pages + i); break; - case GUP_LONGTERM_BENCHMARK: - nr = get_user_pages(addr, nr, - gup->flags | FOLL_LONGTERM, - pages + i, NULL); - break; case GUP_BENCHMARK: nr = get_user_pages(addr, nr, gup->flags, pages + i, NULL); @@ -159,7 +153,6 @@ static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd, switch (cmd) { case GUP_FAST_BENCHMARK: - case GUP_LONGTERM_BENCHMARK: case GUP_BENCHMARK: case PIN_FAST_BENCHMARK: case PIN_LONGTERM_BENCHMARK: diff --git a/tools/testing/selftests/vm/gup_benchmark.c b/tools/testing/selftests/vm/gup_benchmark.c index 03928e47a86f..836b7082db13 100644 --- a/tools/testing/selftests/vm/gup_benchmark.c +++ b/tools/testing/selftests/vm/gup_benchmark.c @@ -15,7 +15,7 @@ #define PAGE_SIZE sysconf(_SC_PAGESIZE) #define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark) -#define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) +/* Command 2 has been deleted. */ #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) /* @@ -49,7 +49,7 @@ int main(int argc, char **argv) char *file = "/dev/zero"; char *p; - while ((opt = getopt(argc, argv, "m:r:n:f:abctTLUuwSH")) != -1) { + while ((opt = getopt(argc, argv, "m:r:n:f:abctTUuwSH")) != -1) { switch (opt) { case 'a': cmd = PIN_FAST_BENCHMARK; @@ -75,9 +75,6 @@ int main(int argc, char **argv) case 'T': thp = 0; break; - case 'L': - cmd = GUP_LONGTERM_BENCHMARK; - break; case 'U': cmd = GUP_BENCHMARK; break;