From mboxrd@z Thu Jan 1 00:00:00 1970 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 ECCE3EB64DA for ; Sun, 16 Jul 2023 09:12:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229760AbjGPJMT (ORCPT ); Sun, 16 Jul 2023 05:12:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229471AbjGPJMT (ORCPT ); Sun, 16 Jul 2023 05:12:19 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0232F102 for ; Sun, 16 Jul 2023 02:12:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 71D1B60C55 for ; Sun, 16 Jul 2023 09:12:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 76E83C433C7; Sun, 16 Jul 2023 09:12:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689498736; bh=filOtxVIF5wjibdkTJmYf6x0bzVRlVvmoaygIOgeN38=; h=Subject:To:Cc:From:Date:From; b=DCvYt8FrWmGdlMPTEObpvL1ejVj23As93fIl2Uzy+U51nJCAtUVcov+KQp1YOxcCZ TeGty03s3H8f9olt6w8H7ha9+cq7tzFRr9TPbM7JSPSMR5DJq6ZNNHNtD1MQD8hKjj d1L/1Nw1A/EEmUmOnca6Zevav7r7xBQue7GCXZPI= Subject: FAILED: patch "[PATCH] mm/damon/ops-common: atomically test and clear young on ptes" failed to apply to 5.15-stable tree To: ryan.roberts@arm.com, akpm@linux-foundation.org, hch@lst.de, kirill.shutemov@linux.intel.com, lstoakes@gmail.com, rppt@kernel.org, sj@kernel.org, stable@vger.kernel.org, urezki@gmail.com, willy@infradead.org, yuzhao@google.com, ziy@nvidia.com Cc: From: Date: Sun, 16 Jul 2023 11:12:14 +0200 Message-ID: <2023071613-reminder-relapse-b922@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x c11d34fa139e4b0fb4249a30f37b178353533fa1 # git commit -s git send-email --to '' --in-reply-to '2023071613-reminder-relapse-b922@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: c11d34fa139e ("mm/damon/ops-common: atomically test and clear young on ptes and pmds") 72c33ef4c02e ("mm/damon: replace pmd_huge() with pmd_trans_huge() for THP") c8b9aff41930 ("mm/damon: validate if the pmd entry is present before accessing") 02e34fff195d ("mm: damon: use HPAGE_PMD_SIZE") 198f0f4c58b9 ("mm/damon/vaddr,paddr: support pageout prioritization") 57223ac29584 ("mm/damon/paddr: support the pageout scheme") a28397beb55b ("mm/damon: implement primitives for physical address space monitoring") 46c3a0accdc4 ("mm/damon/vaddr: separate commonly usable functions") 6dea8add4d28 ("mm/damon/vaddr: support DAMON-based Operation Schemes") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c11d34fa139e4b0fb4249a30f37b178353533fa1 Mon Sep 17 00:00:00 2001 From: Ryan Roberts Date: Fri, 2 Jun 2023 10:29:47 +0100 Subject: [PATCH] mm/damon/ops-common: atomically test and clear young on ptes and pmds It is racy to non-atomically read a pte, then clear the young bit, then write it back as this could discard dirty information. Further, it is bad practice to directly set a pte entry within a table. Instead clearing young must go through the arch-provided helper, ptep_test_and_clear_young() to ensure it is modified atomically and to give the arch code visibility and allow it to check (and potentially modify) the operation. Link: https://lkml.kernel.org/r/20230602092949.545577-3-ryan.roberts@arm.com Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces"). Signed-off-by: Ryan Roberts Reviewed-by: Zi Yan Reviewed-by: SeongJae Park Reviewed-by: Mike Rapoport (IBM) Cc: Christoph Hellwig Cc: Kirill A. Shutemov Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Uladzislau Rezki (Sony) Cc: Yu Zhao Cc: Signed-off-by: Andrew Morton diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c index cc63cf953636..acc264b97903 100644 --- a/mm/damon/ops-common.c +++ b/mm/damon/ops-common.c @@ -37,7 +37,7 @@ struct folio *damon_get_folio(unsigned long pfn) return folio; } -void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr) +void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr) { bool referenced = false; struct folio *folio = damon_get_folio(pte_pfn(*pte)); @@ -45,13 +45,11 @@ void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr) if (!folio) return; - if (pte_young(*pte)) { + if (ptep_test_and_clear_young(vma, addr, pte)) referenced = true; - *pte = pte_mkold(*pte); - } #ifdef CONFIG_MMU_NOTIFIER - if (mmu_notifier_clear_young(mm, addr, addr + PAGE_SIZE)) + if (mmu_notifier_clear_young(vma->vm_mm, addr, addr + PAGE_SIZE)) referenced = true; #endif /* CONFIG_MMU_NOTIFIER */ @@ -62,7 +60,7 @@ void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr) folio_put(folio); } -void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr) +void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr) { #ifdef CONFIG_TRANSPARENT_HUGEPAGE bool referenced = false; @@ -71,13 +69,11 @@ void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr) if (!folio) return; - if (pmd_young(*pmd)) { + if (pmdp_test_and_clear_young(vma, addr, pmd)) referenced = true; - *pmd = pmd_mkold(*pmd); - } #ifdef CONFIG_MMU_NOTIFIER - if (mmu_notifier_clear_young(mm, addr, addr + HPAGE_PMD_SIZE)) + if (mmu_notifier_clear_young(vma->vm_mm, addr, addr + HPAGE_PMD_SIZE)) referenced = true; #endif /* CONFIG_MMU_NOTIFIER */ diff --git a/mm/damon/ops-common.h b/mm/damon/ops-common.h index 14f4bc69f29b..18d837d11bce 100644 --- a/mm/damon/ops-common.h +++ b/mm/damon/ops-common.h @@ -9,8 +9,8 @@ struct folio *damon_get_folio(unsigned long pfn); -void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr); -void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr); +void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr); +void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr); int damon_cold_score(struct damon_ctx *c, struct damon_region *r, struct damos *s); diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c index 467b99166b43..5b3a3463d078 100644 --- a/mm/damon/paddr.c +++ b/mm/damon/paddr.c @@ -24,9 +24,9 @@ static bool __damon_pa_mkold(struct folio *folio, struct vm_area_struct *vma, while (page_vma_mapped_walk(&pvmw)) { addr = pvmw.address; if (pvmw.pte) - damon_ptep_mkold(pvmw.pte, vma->vm_mm, addr); + damon_ptep_mkold(pvmw.pte, vma, addr); else - damon_pmdp_mkold(pvmw.pmd, vma->vm_mm, addr); + damon_pmdp_mkold(pvmw.pmd, vma, addr); } return true; } diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index 1fec16d7263e..37994fb6120c 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -311,7 +311,7 @@ static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr, } if (pmd_trans_huge(*pmd)) { - damon_pmdp_mkold(pmd, walk->mm, addr); + damon_pmdp_mkold(pmd, walk->vma, addr); spin_unlock(ptl); return 0; } @@ -323,7 +323,7 @@ static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr, pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); if (!pte_present(*pte)) goto out; - damon_ptep_mkold(pte, walk->mm, addr); + damon_ptep_mkold(pte, walk->vma, addr); out: pte_unmap_unlock(pte, ptl); return 0;