From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A67715359A for ; Thu, 2 May 2024 16:11:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714666311; cv=none; b=cLcaOBux4CZFmCI+hflI/srMPJ5ruV/is3AzF0Cesq1GyzHqdJjLuTe1xdLDMsmj/gcDEn4DLZh23ocDTWib9y8yrbMBnlwj4NPxscnSKA8VShXGiDfHzEaud1PSMy2HozFRz0SbnK/qYHVOpbR8QtcLq7N/e+m+SCUWDjzUHdw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714666311; c=relaxed/simple; bh=EX26v2tnNfW5LoOILWXsoPdEORO90YxTW9STH5wBC8Y=; h=Date:To:From:Subject:Message-Id; b=JaSxo0YD6bJot7hzQbiuZErX0wsozrE2D1W8JOzkviWKUKPenO7JkASwGO8xcfEyq6H9gCWep8cb6bt2Ph6SGwuDcliZaylo19iTE0qiBJaG1Ld/n70m/bT6L+gCcT2hznKIyJsARfskn0QT2JZtj46yDjVDFNk2W+4vIwpSlRg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=GMraeClZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="GMraeClZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CDB2C113CC; Thu, 2 May 2024 16:11:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1714666311; bh=EX26v2tnNfW5LoOILWXsoPdEORO90YxTW9STH5wBC8Y=; h=Date:To:From:Subject:From; b=GMraeClZsO8gmySm06snVPG7MJ17NYUTnolrB/IhCvoSS7l3XUVNXvh+tzVcj4rqo qR587DzHytQjAVKg+aPRBM29knRiI6cCWXesjLsEVqP2nLHXRpbPvS5Sw0Oym5axFj N+oDzmIHWwdRBYGA227+tJpR++BnWN3hrbbIBsHM= Date: Thu, 02 May 2024 09:11:49 -0700 To: mm-commits@vger.kernel.org,zokeefe@google.com,ziy@nvidia.com,xiehuan09@gmail.com,willy@infradead.org,wangkefeng.wang@huawei.com,songmuchun@bytedance.com,sj@kernel.org,shy828301@gmail.com,ryan.roberts@arm.com,peterx@redhat.com,minchan@kernel.org,mhocko@suse.com,maskray@google.com,fengwei.yin@intel.com,david@redhat.com,21cnbao@gmail.com,ioworker0@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop.patch added to mm-unstable branch Message-Id: <20240502161151.1CDB2C113CC@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/rmap: integrate PMD-mapped folio splitting into pagewalk loop has been added to the -mm mm-unstable branch. Its filename is mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Lance Yang Subject: mm/rmap: integrate PMD-mapped folio splitting into pagewalk loop Date: Wed, 1 May 2024 12:26:59 +0800 In preparation for supporting try_to_unmap_one() to unmap PMD-mapped folios, start the pagewalk first, then call split_huge_pmd_address() to split the folio. Link: https://lkml.kernel.org/r/20240501042700.83974-3-ioworker0@gmail.com Signed-off-by: Lance Yang Suggested-by: David Hildenbrand Tested-by: SeongJae Park Cc: Barry Song <21cnbao@gmail.com> Cc: Fangrui Song Cc: Jeff Xie Cc: Kefeng Wang Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Minchan Kim Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yang Shi Cc: Yin Fengwei Cc: Zach O'Keefe Cc: Zi Yan Signed-off-by: Andrew Morton --- include/linux/huge_mm.h | 20 ++++++++++++++++++ mm/huge_memory.c | 42 +++++++++++++++++++------------------- mm/rmap.c | 24 ++++++++++++++++----- 3 files changed, 60 insertions(+), 26 deletions(-) --- a/include/linux/huge_mm.h~mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop +++ a/include/linux/huge_mm.h @@ -409,6 +409,20 @@ static inline bool thp_migration_support return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION); } +void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmd, bool freeze, struct folio *folio); + +static inline void align_huge_pmd_range(struct vm_area_struct *vma, + unsigned long *start, + unsigned long *end) +{ + *start = ALIGN(*start, HPAGE_PMD_SIZE); + *end = ALIGN_DOWN(*end, HPAGE_PMD_SIZE); + + VM_WARN_ON_ONCE(vma->vm_start > *start); + VM_WARN_ON_ONCE(vma->vm_end < *end); +} + #else /* CONFIG_TRANSPARENT_HUGEPAGE */ static inline bool folio_test_pmd_mappable(struct folio *folio) @@ -471,6 +485,12 @@ static inline void __split_huge_pmd(stru unsigned long address, bool freeze, struct folio *folio) {} static inline void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address, bool freeze, struct folio *folio) {} +static inline void split_huge_pmd_locked(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmd, + bool freeze, struct folio *folio) {} +static inline void align_huge_pmd_range(struct vm_area_struct *vma, + unsigned long *start, + unsigned long *end) {} #define split_huge_pud(__vma, __pmd, __address) \ do { } while (0) --- a/mm/huge_memory.c~mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop +++ a/mm/huge_memory.c @@ -2583,6 +2583,27 @@ static void __split_huge_pmd_locked(stru pmd_populate(mm, pmd, pgtable); } +void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmd, bool freeze, struct folio *folio) +{ + VM_WARN_ON_ONCE(folio && !folio_test_pmd_mappable(folio)); + VM_WARN_ON_ONCE(!IS_ALIGNED(address, HPAGE_PMD_SIZE)); + VM_WARN_ON_ONCE(folio && !folio_test_locked(folio)); + VM_BUG_ON(freeze && !folio); + + /* + * When the caller requests to set up a migration entry, we + * require a folio to check the PMD against. Otherwise, there + * is a risk of replacing the wrong folio. + */ + if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd) || + is_pmd_migration_entry(*pmd)) { + if (folio && folio != pmd_folio(*pmd)) + return; + __split_huge_pmd_locked(vma, pmd, address, freeze); + } +} + void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long address, bool freeze, struct folio *folio) { @@ -2594,26 +2615,7 @@ void __split_huge_pmd(struct vm_area_str (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE); mmu_notifier_invalidate_range_start(&range); ptl = pmd_lock(vma->vm_mm, pmd); - - /* - * If caller asks to setup a migration entry, we need a folio to check - * pmd against. Otherwise we can end up replacing wrong folio. - */ - VM_BUG_ON(freeze && !folio); - VM_WARN_ON_ONCE(folio && !folio_test_locked(folio)); - - if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd) || - is_pmd_migration_entry(*pmd)) { - /* - * It's safe to call pmd_page when folio is set because it's - * guaranteed that pmd is present. - */ - if (folio && folio != pmd_folio(*pmd)) - goto out; - __split_huge_pmd_locked(vma, pmd, range.start, freeze); - } - -out: + split_huge_pmd_locked(vma, range.start, pmd, freeze, folio); spin_unlock(ptl); mmu_notifier_invalidate_range_end(&range); } --- a/mm/rmap.c~mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop +++ a/mm/rmap.c @@ -1637,9 +1637,6 @@ static bool try_to_unmap_one(struct foli if (flags & TTU_SYNC) pvmw.flags = PVMW_SYNC; - if (flags & TTU_SPLIT_HUGE_PMD) - split_huge_pmd_address(vma, address, false, folio); - /* * For THP, we have to assume the worse case ie pmd for invalidation. * For hugetlb, it could be much worse if we need to do pud @@ -1651,6 +1648,8 @@ static bool try_to_unmap_one(struct foli range.end = vma_address_end(&pvmw); mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, address, range.end); + if (flags & TTU_SPLIT_HUGE_PMD) + align_huge_pmd_range(vma, &range.start, &range.end); if (folio_test_hugetlb(folio)) { /* * If sharing is possible, start and end will be adjusted @@ -1665,9 +1664,6 @@ static bool try_to_unmap_one(struct foli mmu_notifier_invalidate_range_start(&range); while (page_vma_mapped_walk(&pvmw)) { - /* Unexpected PMD-mapped THP? */ - VM_BUG_ON_FOLIO(!pvmw.pte, folio); - /* * If the folio is in an mlock()d vma, we must not swap it out. */ @@ -1679,6 +1675,22 @@ static bool try_to_unmap_one(struct foli goto walk_done_err; } + if (!pvmw.pte && (flags & TTU_SPLIT_HUGE_PMD)) { + /* + * We temporarily have to drop the PTL and start once + * again from that now-PTE-mapped page table. + */ + split_huge_pmd_locked(vma, range.start, pvmw.pmd, false, + folio); + pvmw.pmd = NULL; + spin_unlock(pvmw.ptl); + flags &= ~TTU_SPLIT_HUGE_PMD; + continue; + } + + /* Unexpected PMD-mapped THP? */ + VM_BUG_ON_FOLIO(!pvmw.pte, folio); + pfn = pte_pfn(ptep_get(pvmw.pte)); subpage = folio_page(folio, pfn - folio_pfn(folio)); address = pvmw.address; _ Patches currently in -mm which might be from ioworker0@gmail.com are mm-madvise-introduce-clear_young_dirty_ptes-batch-helper.patch mm-arm64-override-clear_young_dirty_ptes-batch-helper.patch mm-memory-add-any_dirty-optional-pointer-to-folio_pte_batch.patch mm-madvise-optimize-lazyfreeing-with-mthp-in-madvise_free.patch mm-rmap-remove-duplicated-exit-code-in-pagewalk-loop.patch mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop.patch mm-vmscan-avoid-split-lazyfree-thp-during-shrink_folio_list.patch