From patchwork Wed Jul 24 01:26:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: john.hubbard@gmail.com X-Patchwork-Id: 11056169 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D19A16C5 for ; Wed, 24 Jul 2019 06:54:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BEE2F286E0 for ; Wed, 24 Jul 2019 06:54:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B256328770; Wed, 24 Jul 2019 06:54:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E13D22876D for ; Wed, 24 Jul 2019 06:54:30 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2BF4889FC3; Wed, 24 Jul 2019 06:54:26 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by gabe.freedesktop.org (Postfix) with ESMTPS id 07B776E419 for ; Wed, 24 Jul 2019 01:26:11 +0000 (UTC) Received: by mail-pg1-x542.google.com with SMTP id i70so9556233pgd.4 for ; Tue, 23 Jul 2019 18:26:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bhISJM8Puuah8x38nAQ9RovICw9tsVA8mnG10T+jR8A=; b=Z0iiyoFm55nwnjvu/2kgbVtPqpMuhhjTnrJFmvXJ30VXy50xwX9eRzySfy/xb55cZm HToXwaLLgc08p/bm9QxVa45xbkiE3/r9fA7IF/+SIF/zae39wBz+DVmsPsdZEqNBrI1v 7tYV2CtBcjJ385Jld1KDiNB6o1s1QoG31Waa3V8LFPHAH4ii/9GI6UKR8JMxbqUTM8JV bN4UjmADvf2U5vK4fgac+R1YKfI1+gz995YdMXHk0o/GJNqcJLyCAWCSxBOEAr5x//+f Erw2jf17xJHT8/50NtAO6Ffu0IjQ3e510RucOzrLQEjRoMO6MzWqAAyWFe4SCZF8wyYP Sszg== X-Gm-Message-State: APjAAAVsRvnf6fPQkejlAnA22zelc3Je0LRuMzpKag5ZCw44z3a3cvGv +MDDew6WRbcU+JNwtbLNBTY= X-Google-Smtp-Source: APXvYqyCdkt4ibt9fIPkrzzNl+NEdl1RVCVRLumtAtbSj8Bu7fq8bTQqZu6WuCt/OTVocCDq4UlCjg== X-Received: by 2002:a63:1d2:: with SMTP id 201mr44242875pgb.307.1563931571511; Tue, 23 Jul 2019 18:26:11 -0700 (PDT) Received: from blueforge.nvidia.com (searspoint.nvidia.com. [216.228.112.21]) by smtp.gmail.com with ESMTPSA id k36sm45950119pgl.42.2019.07.23.18.26.10 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 23 Jul 2019 18:26:11 -0700 (PDT) From: john.hubbard@gmail.com X-Google-Original-From: jhubbard@nvidia.com To: Andrew Morton Subject: [PATCH v2 1/3] mm/gup: add make_dirty arg to put_user_pages_dirty_lock() Date: Tue, 23 Jul 2019 18:26:04 -0700 Message-Id: <20190724012606.25844-2-jhubbard@nvidia.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724012606.25844-1-jhubbard@nvidia.com> References: <20190724012606.25844-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public X-Mailman-Approved-At: Wed, 24 Jul 2019 06:54:25 +0000 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bhISJM8Puuah8x38nAQ9RovICw9tsVA8mnG10T+jR8A=; b=Q/bgJr1JpzOWXoz2byTw4Q2bsTLJg5zwbfU1Qxt2NTN2sBWna+7J88KpXhgorvqtwI iMpwtqcxs7wX4w42OJVdwYlIJDSymjTz4roIqdstm0FQI/jrrxkg+vZ/mgxRYtcadkXU l0KA9TxZBJQ16F+IeHdWQLriA8ZHaFIwVxzyNIsHvgz+eTvMncvM57iXnsIjClp7FD5f yqVW6rtGwTRYS5MC4HU3svbbGRttlcThivkgYGSDGxA+whP8bRqJQna3oXzvlDkWZCT7 j68RFQ0OPCQ8GXAJj/VHcRIxhA3JiyVaDM/SLvQZ4TsClt8txpttAFV29WhVFIq1L96R PJfg== X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Boaz Harrosh , Jan Kara , David Airlie , Dave Chinner , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, Ira Weiny , Christoph Hellwig , Sage Weil , Miklos Szeredi , linux-rdma@vger.kernel.org, Matthew Wilcox , Jason Gunthorpe , Johannes Thumshirn , Ilya Dryomov , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , John Hubbard , Santosh Shilimkar , Ming Lei , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Alexander Viro , Dan Williams , Magnus Karlsson , Jens Axboe , netdev@vger.kernel.org, LKML , Yan Zheng , bpf@vger.kernel.org, "David S . Miller" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: John Hubbard Provide more capable variation of put_user_pages_dirty_lock(), and delete put_user_pages_dirty(). This is based on the following: 1. Lots of call sites become simpler if a bool is passed into put_user_page*(), instead of making the call site choose which put_user_page*() variant to call. 2. Christoph Hellwig's observation that set_page_dirty_lock() is usually correct, and set_page_dirty() is usually a bug, or at least questionable, within a put_user_page*() calling chain. This leads to the following API choices: * put_user_pages_dirty_lock(page, npages, make_dirty) * There is no put_user_pages_dirty(). You have to hand code that, in the rare case that it's required. Cc: Matthew Wilcox Cc: Jan Kara Cc: Christoph Hellwig Cc: Ira Weiny Cc: Jason Gunthorpe Signed-off-by: John Hubbard --- drivers/infiniband/core/umem.c | 5 +- drivers/infiniband/hw/hfi1/user_pages.c | 5 +- drivers/infiniband/hw/qib/qib_user_pages.c | 5 +- drivers/infiniband/hw/usnic/usnic_uiom.c | 5 +- drivers/infiniband/sw/siw/siw_mem.c | 8 +- include/linux/mm.h | 5 +- mm/gup.c | 116 +++++++++------------ 7 files changed, 59 insertions(+), 90 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 08da840ed7ee..965cf9dea71a 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -54,10 +54,7 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d for_each_sg_page(umem->sg_head.sgl, &sg_iter, umem->sg_nents, 0) { page = sg_page_iter_page(&sg_iter); - if (umem->writable && dirty) - put_user_pages_dirty_lock(&page, 1); - else - put_user_page(page); + put_user_pages_dirty_lock(&page, 1, umem->writable && dirty); } sg_free_table(&umem->sg_head); diff --git a/drivers/infiniband/hw/hfi1/user_pages.c b/drivers/infiniband/hw/hfi1/user_pages.c index b89a9b9aef7a..469acb961fbd 100644 --- a/drivers/infiniband/hw/hfi1/user_pages.c +++ b/drivers/infiniband/hw/hfi1/user_pages.c @@ -118,10 +118,7 @@ int hfi1_acquire_user_pages(struct mm_struct *mm, unsigned long vaddr, size_t np void hfi1_release_user_pages(struct mm_struct *mm, struct page **p, size_t npages, bool dirty) { - if (dirty) - put_user_pages_dirty_lock(p, npages); - else - put_user_pages(p, npages); + put_user_pages_dirty_lock(p, npages, dirty); if (mm) { /* during close after signal, mm can be NULL */ atomic64_sub(npages, &mm->pinned_vm); diff --git a/drivers/infiniband/hw/qib/qib_user_pages.c b/drivers/infiniband/hw/qib/qib_user_pages.c index bfbfbb7e0ff4..6bf764e41891 100644 --- a/drivers/infiniband/hw/qib/qib_user_pages.c +++ b/drivers/infiniband/hw/qib/qib_user_pages.c @@ -40,10 +40,7 @@ static void __qib_release_user_pages(struct page **p, size_t num_pages, int dirty) { - if (dirty) - put_user_pages_dirty_lock(p, num_pages); - else - put_user_pages(p, num_pages); + put_user_pages_dirty_lock(p, num_pages, dirty); } /** diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c index 0b0237d41613..62e6ffa9ad78 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c @@ -75,10 +75,7 @@ static void usnic_uiom_put_pages(struct list_head *chunk_list, int dirty) for_each_sg(chunk->page_list, sg, chunk->nents, i) { page = sg_page(sg); pa = sg_phys(sg); - if (dirty) - put_user_pages_dirty_lock(&page, 1); - else - put_user_page(page); + put_user_pages_dirty_lock(&page, 1, dirty); usnic_dbg("pa: %pa\n", &pa); } kfree(chunk); diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c index 67171c82b0c4..358d440efa11 100644 --- a/drivers/infiniband/sw/siw/siw_mem.c +++ b/drivers/infiniband/sw/siw/siw_mem.c @@ -65,13 +65,7 @@ static void siw_free_plist(struct siw_page_chunk *chunk, int num_pages, { struct page **p = chunk->plist; - while (num_pages--) { - if (!PageDirty(*p) && dirty) - put_user_pages_dirty_lock(p, 1); - else - put_user_page(*p); - p++; - } + put_user_pages_dirty_lock(chunk->plist, num_pages, dirty); } void siw_umem_release(struct siw_umem *umem, bool dirty) diff --git a/include/linux/mm.h b/include/linux/mm.h index 0334ca97c584..9759b6a24420 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1057,8 +1057,9 @@ static inline void put_user_page(struct page *page) put_page(page); } -void put_user_pages_dirty(struct page **pages, unsigned long npages); -void put_user_pages_dirty_lock(struct page **pages, unsigned long npages); +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); #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) diff --git a/mm/gup.c b/mm/gup.c index 98f13ab37bac..d14bd362ec28 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -29,85 +29,71 @@ struct follow_page_context { unsigned int page_mask; }; -typedef int (*set_dirty_func_t)(struct page *page); - -static void __put_user_pages_dirty(struct page **pages, - unsigned long npages, - set_dirty_func_t sdf) -{ - unsigned long index; - - for (index = 0; index < npages; index++) { - struct page *page = compound_head(pages[index]); - - /* - * Checking PageDirty at this point may race with - * clear_page_dirty_for_io(), but that's OK. Two key cases: - * - * 1) This code sees the page as already dirty, so it skips - * the call to sdf(). That could happen because - * clear_page_dirty_for_io() called page_mkclean(), - * followed by set_page_dirty(). However, now the page is - * going to get written back, which meets the original - * intention of setting it dirty, so all is well: - * clear_page_dirty_for_io() goes on to call - * TestClearPageDirty(), and write the page back. - * - * 2) This code sees the page as clean, so it calls sdf(). - * The page stays dirty, despite being written back, so it - * gets written back again in the next writeback cycle. - * This is harmless. - */ - if (!PageDirty(page)) - sdf(page); - - put_user_page(page); - } -} - /** - * put_user_pages_dirty() - release and dirty an array of gup-pinned pages - * @pages: array of pages to be marked dirty and released. + * put_user_pages_dirty_lock() - release and optionally dirty gup-pinned pages + * @pages: array of pages to be maybe marked dirty, and definitely released. * @npages: number of pages in the @pages array. + * @make_dirty: whether to mark the pages dirty * * "gup-pinned page" refers to a page that has had one of the get_user_pages() * variants called on that page. * * For each page in the @pages array, make that page (or its head page, if a - * compound page) dirty, if it was previously listed as clean. Then, release - * the page using put_user_page(). + * compound page) dirty, if @make_dirty is true, and if the page was previously + * listed as clean. In any case, releases all pages using put_user_page(), + * possibly via put_user_pages(), for the non-dirty case. * * Please see the put_user_page() documentation for details. * - * set_page_dirty(), which does not lock the page, is used here. - * Therefore, it is the caller's responsibility to ensure that this is - * safe. If not, then put_user_pages_dirty_lock() should be called instead. + * set_page_dirty_lock() is used internally. If instead, set_page_dirty() is + * required, then the caller should a) verify that this is really correct, + * because _lock() is usually required, and b) hand code it: + * set_page_dirty_lock(), put_user_page(). * */ -void put_user_pages_dirty(struct page **pages, unsigned long npages) +void put_user_pages_dirty_lock(struct page **pages, unsigned long npages, + bool make_dirty) { - __put_user_pages_dirty(pages, npages, set_page_dirty); -} -EXPORT_SYMBOL(put_user_pages_dirty); + unsigned long index; -/** - * put_user_pages_dirty_lock() - release and dirty an array of gup-pinned pages - * @pages: array of pages to be marked dirty and released. - * @npages: number of pages in the @pages array. - * - * For each page in the @pages array, make that page (or its head page, if a - * compound page) dirty, if it was previously listed as clean. Then, release - * the page using put_user_page(). - * - * Please see the put_user_page() documentation for details. - * - * This is just like put_user_pages_dirty(), except that it invokes - * set_page_dirty_lock(), instead of set_page_dirty(). - * - */ -void put_user_pages_dirty_lock(struct page **pages, unsigned long npages) -{ - __put_user_pages_dirty(pages, npages, set_page_dirty_lock); + /* + * TODO: this can be optimized for huge pages: if a series of pages is + * physically contiguous and part of the same compound page, then a + * single operation to the head page should suffice. + */ + + if (!make_dirty) { + put_user_pages(pages, npages); + return; + } + + for (index = 0; index < npages; index++) { + struct page *page = compound_head(pages[index]); + /* + * Checking PageDirty at this point may race with + * clear_page_dirty_for_io(), but that's OK. Two key + * cases: + * + * 1) This code sees the page as already dirty, so it + * skips the call to set_page_dirty(). That could happen + * because clear_page_dirty_for_io() called + * page_mkclean(), followed by set_page_dirty(). + * However, now the page is going to get written back, + * which meets the original intention of setting it + * dirty, so all is well: clear_page_dirty_for_io() goes + * on to call TestClearPageDirty(), and write the page + * back. + * + * 2) This code sees the page as clean, so it calls + * set_page_dirty(). The page stays dirty, despite being + * written back, so it gets written back again in the + * next writeback cycle. This is harmless. + */ + if (!PageDirty(page)) + set_page_dirty_lock(page); + break; + put_user_page(page); + } } EXPORT_SYMBOL(put_user_pages_dirty_lock);