From patchwork Thu Nov 3 10:07:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muhammad Usama Anjum X-Patchwork-Id: 13029856 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8EAEAC4332F for ; Thu, 3 Nov 2022 10:08:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231246AbiKCKIH (ORCPT ); Thu, 3 Nov 2022 06:08:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231255AbiKCKH6 (ORCPT ); Thu, 3 Nov 2022 06:07:58 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63646394; Thu, 3 Nov 2022 03:07:57 -0700 (PDT) Received: from localhost.localdomain (unknown [39.45.244.84]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: usama.anjum) by madras.collabora.co.uk (Postfix) with ESMTPSA id F1B8F6602936; Thu, 3 Nov 2022 10:07:50 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1667470076; bh=MLOajoALxs2BA+DAlpPUi9P0UdFtJcqV/tFJX2ymRCg=; h=From:To:Subject:Date:In-Reply-To:References:From; b=VBORngxRE/I3r1ilvd5xFr6Q8FqWKImM+odODVIEno95GBE3mTV9aUiCL43ohYPa7 35vsb2hGq3Z91/DOmVmdXUovT0a03NshSCVrEx/GiLxO1IutPLbxABoYSLFcXIPlUh DbDcozWzkymFpf2VAOVY1B6dd8PCqseGsRAiWSjzKMkGEIRIS3nT556cEFJ2lWMkYQ ApPukZJxB0Upr8sxaybK593LRpVKNjujNtuNbO2zyZeGIpd5oc1E3zgvY2SZ1wk9Ks VSMOTpNTemWScPmQ/3FuPOGGyLJcNASO3UiDIKg2jPzFvNZGlmIRkuPUT+pTv6Klaf aGXoE5A5hPP+Q== From: Muhammad Usama Anjum To: Andrei Vagin , Danylo Mocherniuk , Alexander Viro , Andrew Morton , =?utf-8?b?TWljaGHFgiBNaXJvc8WC?= =?utf-8?b?YXc=?= , Suren Baghdasaryan , Greg KH , Christian Brauner , Peter Xu , Yang Shi , Vlastimil Babka , "Zach O'Keefe" , "Matthew Wilcox (Oracle)" , "Gustavo A. R. Silva" , Dan Williams , Muhammad Usama Anjum , kernel@collabora.com, Gabriel Krisman Bertazi , David Hildenbrand , Peter Enderborg , "open list : KERNEL SELFTEST FRAMEWORK" , Shuah Khan , open list , "open list : PROC FILESYSTEM" , "open list : MEMORY MANAGEMENT" Subject: [PATCH v4 1/3] fs/proc/task_mmu: update functions to clear the soft-dirty PTE bit Date: Thu, 3 Nov 2022 15:07:34 +0500 Message-Id: <20221103100736.2356351-2-usama.anjum@collabora.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221103100736.2356351-1-usama.anjum@collabora.com> References: <20221103100736.2356351-1-usama.anjum@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Update the clear_soft_dirty() and clear_soft_dirty_pmd() to optionally clear and return the status if page is dirty. Signed-off-by: Muhammad Usama Anjum --- Changes in v2: - Move back the functions back to their original file --- fs/proc/task_mmu.c | 82 ++++++++++++++++++++++++++++------------------ 1 file changed, 51 insertions(+), 31 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 8a74cdcc9af0..8235c536ac70 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1095,8 +1095,8 @@ static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, return page_maybe_dma_pinned(page); } -static inline void clear_soft_dirty(struct vm_area_struct *vma, - unsigned long addr, pte_t *pte) +static inline bool check_soft_dirty(struct vm_area_struct *vma, + unsigned long addr, pte_t *pte, bool clear) { /* * The soft-dirty tracker uses #PF-s to catch writes @@ -1105,55 +1105,75 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma, * of how soft-dirty works. */ pte_t ptent = *pte; + int dirty = 0; if (pte_present(ptent)) { pte_t old_pte; - if (pte_is_pinned(vma, addr, ptent)) - return; - old_pte = ptep_modify_prot_start(vma, addr, pte); - ptent = pte_wrprotect(old_pte); - ptent = pte_clear_soft_dirty(ptent); - ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); + dirty = pte_soft_dirty(ptent); + + if (dirty && clear && !pte_is_pinned(vma, addr, ptent)) { + old_pte = ptep_modify_prot_start(vma, addr, pte); + ptent = pte_wrprotect(old_pte); + ptent = pte_clear_soft_dirty(ptent); + ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent); + } } else if (is_swap_pte(ptent)) { - ptent = pte_swp_clear_soft_dirty(ptent); - set_pte_at(vma->vm_mm, addr, pte, ptent); + dirty = pte_swp_soft_dirty(ptent); + + if (dirty && clear) { + ptent = pte_swp_clear_soft_dirty(ptent); + set_pte_at(vma->vm_mm, addr, pte, ptent); + } } + + return !!dirty; } #else -static inline void clear_soft_dirty(struct vm_area_struct *vma, - unsigned long addr, pte_t *pte) +static inline bool check_soft_dirty(struct vm_area_struct *vma, + unsigned long addr, pte_t *pte, bool clear) { + return false; } #endif #if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE) -static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, - unsigned long addr, pmd_t *pmdp) +static inline bool check_soft_dirty_pmd(struct vm_area_struct *vma, + unsigned long addr, pmd_t *pmdp, bool clear) { pmd_t old, pmd = *pmdp; + int dirty = 0; if (pmd_present(pmd)) { - /* See comment in change_huge_pmd() */ - old = pmdp_invalidate(vma, addr, pmdp); - if (pmd_dirty(old)) - pmd = pmd_mkdirty(pmd); - if (pmd_young(old)) - pmd = pmd_mkyoung(pmd); - - pmd = pmd_wrprotect(pmd); - pmd = pmd_clear_soft_dirty(pmd); - - set_pmd_at(vma->vm_mm, addr, pmdp, pmd); + dirty = pmd_soft_dirty(pmd); + if (dirty && clear) { + /* See comment in change_huge_pmd() */ + old = pmdp_invalidate(vma, addr, pmdp); + if (pmd_dirty(old)) + pmd = pmd_mkdirty(pmd); + if (pmd_young(old)) + pmd = pmd_mkyoung(pmd); + + pmd = pmd_wrprotect(pmd); + pmd = pmd_clear_soft_dirty(pmd); + + set_pmd_at(vma->vm_mm, addr, pmdp, pmd); + } } else if (is_migration_entry(pmd_to_swp_entry(pmd))) { - pmd = pmd_swp_clear_soft_dirty(pmd); - set_pmd_at(vma->vm_mm, addr, pmdp, pmd); + dirty = pmd_swp_soft_dirty(pmd); + + if (dirty && clear) { + pmd = pmd_swp_clear_soft_dirty(pmd); + set_pmd_at(vma->vm_mm, addr, pmdp, pmd); + } } + return !!dirty; } #else -static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma, - unsigned long addr, pmd_t *pmdp) +static inline bool check_soft_dirty_pmd(struct vm_area_struct *vma, + unsigned long addr, pmd_t *pmdp, bool clear) { + return false; } #endif @@ -1169,7 +1189,7 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, ptl = pmd_trans_huge_lock(pmd, vma); if (ptl) { if (cp->type == CLEAR_REFS_SOFT_DIRTY) { - clear_soft_dirty_pmd(vma, addr, pmd); + check_soft_dirty_pmd(vma, addr, pmd, true); goto out; } @@ -1195,7 +1215,7 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, ptent = *pte; if (cp->type == CLEAR_REFS_SOFT_DIRTY) { - clear_soft_dirty(vma, addr, pte); + check_soft_dirty(vma, addr, pte, true); continue; }