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2022-05-19mm: khugepaged: introduce khugepaged_enter_vma() helperYang Shi1-3/+3
The khugepaged_enter_vma_merge() actually does as the same thing as the khugepaged_enter() section called by shmem_mmap(), so consolidate them into one helper and rename it to khugepaged_enter_vma(). Link: https://lkml.kernel.org/r/20220510203222.24246-8-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Acked-by: Vlastmil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <song@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19mm: khugepaged: make hugepage_vma_check() non-staticYang Shi1-16/+9
The hugepage_vma_check() could be reused by khugepaged_enter() and khugepaged_enter_vma_merge(), but it is static in khugepaged.c. Make it non-static and declare it in khugepaged.h. Link: https://lkml.kernel.org/r/20220510203222.24246-7-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <song@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19mm: khugepaged: make khugepaged_enter() void functionYang Shi1-11/+7
The most callers of khugepaged_enter() don't care about the return value. Only dup_mmap(), anonymous THP page fault and MADV_HUGEPAGE handle the error by returning -ENOMEM. Actually it is not harmful for them to ignore the error case either. It also sounds overkilling to fail fork() and page fault early due to khugepaged_enter() error, and MADV_HUGEPAGE does set VM_HUGEPAGE flag regardless of the error. Link: https://lkml.kernel.org/r/20220510203222.24246-6-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Acked-by: Song Liu <song@kernel.org> Acked-by: Vlastmil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <songliubraving@fb.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19mm: thp: only regular file could be THP eligibleYang Shi1-7/+2
Since commit a4aeaa06d45e ("mm: khugepaged: skip huge page collapse for special files"), khugepaged just collapses THP for regular file which is the intended usecase for readonly fs THP. Only show regular file as THP eligible accordingly. And make file_thp_enabled() available for khugepaged too in order to remove duplicate code. Link: https://lkml.kernel.org/r/20220510203222.24246-5-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Acked-by: Song Liu <song@kernel.org> Acked-by: Vlastmil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <songliubraving@fb.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19mm: khugepaged: skip DAX vmaYang Shi1-0/+4
The DAX vma may be seen by khugepaged when the mm has other khugepaged suitable vmas. So khugepaged may try to collapse THP for DAX vma, but it will fail due to page sanity check, for example, page is not on LRU. So it is not harmful, but it is definitely pointless to run khugepaged against DAX vma, so skip it in early check. Link: https://lkml.kernel.org/r/20220510203222.24246-4-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Song Liu <song@kernel.org> Acked-by: Vlastmil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <songliubraving@fb.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19mm: khugepaged: remove redundant check for VM_NO_KHUGEPAGEDYang Shi1-3/+6
The hugepage_vma_check() called by khugepaged_enter_vma_merge() does check VM_NO_KHUGEPAGED. Remove the check from caller and move the check in hugepage_vma_check() up. More checks may be run for VM_NO_KHUGEPAGED vmas, but MADV_HUGEPAGE is definitely not a hot path, so cleaner code does outweigh. Link: https://lkml.kernel.org/r/20220510203222.24246-3-shy828301@gmail.com Signed-off-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Song Liu <song@kernel.org> Acked-by: Vlastmil Babka <vbabka@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <songliubraving@fb.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/khugepaged: don't recycle vma pgtable if uffd-wp registeredPeter Xu1-1/+13
When we're trying to collapse a 2M huge shmem page, don't retract pgtable pmd page if it's registered with uffd-wp, because that pgtable could have pte markers installed. Recycling of that pgtable means we'll lose the pte markers. That could cause data loss for an uffd-wp enabled application on shmem. Instead of disabling khugepaged on these files, simply skip retracting these special VMAs, then the page cache can still be merged into a huge thp, and other mm/vma can still map the range of file with a huge thp when proper. Note that checking VM_UFFD_WP needs to be done with mmap_sem held for write, that avoids race like: khugepaged user thread ========== =========== check VM_UFFD_WP, not set UFFDIO_REGISTER with uffd-wp on shmem wr-protect some pages (install markers) take mmap_sem write lock erase pmd and free pmd page --> pte markers are dropped unnoticed! Link: https://lkml.kernel.org/r/20220405014921.14994-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-09mm/rmap: drop "compound" parameter from page_add_new_anon_rmap()David Hildenbrand1-1/+1
New anonymous pages are always mapped natively: only THP/khugepaged code maps a new compound anonymous page and passes "true". Otherwise, we're just dealing with simple, non-compound pages. Let's give the interface clearer semantics and document these. Remove the PageTransCompound() sanity check from page_add_new_anon_rmap(). Link: https://lkml.kernel.org/r/20220428083441.37290-9-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Rientjes <rientjes@google.com> Cc: Don Dutile <ddutile@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Liang Zhang <zhangliang5@huawei.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Nadav Amit <namit@vmware.com> Cc: Oded Gabbay <oded.gabbay@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-29mm/khugepaged: use vma_is_anonymousxu xin1-2/+2
Clean up the vma->vm_ops usage. Use vma_is_anonymous instead of vma->vm_ops to make it more understandable. Link: https://lkml.kernel.org/r/20220424071642.3234971-1-xu.xin16@zte.com.cn Signed-off-by: xu xin <xu.xin16@zte.com.cn> Reviewed-by: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-03-24mm/khugepaged: remove reuse_swap_page() usageDavid Hildenbrand1-11/+0
reuse_swap_page() currently indicates if we can write to an anon page without COW. A COW is required if the page is shared by multiple processes (either already mapped or via swap entries) or if there is concurrent writeback that cannot tolerate concurrent page modifications. However, in the context of khugepaged we're not actually going to write to a read-only mapped page, we'll copy the page content to our newly allocated THP and map that THP writable. All we have to make sure is that the read-only mapped page we're about to copy won't get reused by another process sharing the page, otherwise, page content would get modified. But that is already guaranteed via multiple mechanisms (e.g., holding a reference, holding the page lock, removing the rmap after copying the page). The swapcache handling was introduced in commit 10359213d05a ("mm: incorporate read-only pages into transparent huge pages") and it sounds like it merely wanted to mimic what do_swap_page() would do when trying to map a page obtained via the swapcache writable. As that logic is unnecessary, let's just remove it, removing the last user of reuse_swap_page(). Link: https://lkml.kernel.org/r/20220131162940.210846-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: David Rientjes <rientjes@google.com> Cc: Don Dutile <ddutile@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Liang Zhang <zhangliang5@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-21mm/rmap: Convert try_to_unmap() to take a folioMatthew Wilcox (Oracle)1-1/+2
Change all three callers and the worker function try_to_unmap_one(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-02-17mm/thp: collapse_file() do try_to_unmap(TTU_BATCH_FLUSH)Hugh Dickins1-2/+8
collapse_file() is using unmap_mapping_pages(1) on each small page found mapped, unlike others (reclaim, migration, splitting, memory-failure) who use try_to_unmap(). There are four advantages to try_to_unmap(): first, its TTU_IGNORE_MLOCK option now avoids leaving mlocked page in pagevec; second, its vma lookup uses i_mmap_lock_read() not i_mmap_lock_write(); third, it breaks out early if page is not mapped everywhere it might be; fourth, its TTU_BATCH_FLUSH option can be used, as in page reclaim, to save up all the TLB flushing until all of the pages have been unmapped. Wild guess: perhaps it was originally written to use try_to_unmap(), but hit the VM_BUG_ON_PAGE(page_mapped) after unmapping, because without TTU_SYNC it may skip page table locks; but unmap_mapping_pages() never skips them, so fixed the issue. I did once hit that VM_BUG_ON_PAGE() since making this change: we could pass TTU_SYNC here, but I think just delete the check - the race is very rare, this is an ordinary small page so we don't need to be so paranoid about mapcount surprises, and the page_ref_freeze() just below already handles the case adequately. Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-02-17mm/munlock: rmap call mlock_vma_page() munlock_vma_page()Hugh Dickins1-2/+2
Add vma argument to mlock_vma_page() and munlock_vma_page(), make them inline functions which check (vma->vm_flags & VM_LOCKED) before calling mlock_page() and munlock_page() in mm/mlock.c. Add bool compound to mlock_vma_page() and munlock_vma_page(): this is because we have understandable difficulty in accounting pte maps of THPs, and if passed a PageHead page, mlock_page() and munlock_page() cannot tell whether it's a pmd map to be counted or a pte map to be ignored. Add vma arg to page_add_file_rmap() and page_remove_rmap(), like the others, and use that to call mlock_vma_page() at the end of the page adds, and munlock_vma_page() at the end of page_remove_rmap() (end or beginning? unimportant, but end was easier for assertions in testing). No page lock is required (although almost all adds happen to hold it): delete the "Serialize with page migration" BUG_ON(!PageLocked(page))s. Certainly page lock did serialize with page migration, but I'm having difficulty explaining why that was ever important. Mlock accounting on THPs has been hard to define, differed between anon and file, involved PageDoubleMap in some places and not others, required clear_page_mlock() at some points. Keep it simple now: just count the pmds and ignore the ptes, there is no reason for ptes to undo pmd mlocks. page_add_new_anon_rmap() callers unchanged: they have long been calling lru_cache_add_inactive_or_unevictable(), which does its own VM_LOCKED handling (it also checks for not VM_SPECIAL: I think that's overcautious, and inconsistent with other checks, that mmap_region() already prevents VM_LOCKED on VM_SPECIAL; but haven't quite convinced myself to change it). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-02-04mm/page_table_check: check entries at pmd levelsPasha Tatashin1-0/+3
syzbot detected a case where the page table counters were not properly updated. syzkaller login: ------------[ cut here ]------------ kernel BUG at mm/page_table_check.c:162! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3099 Comm: pasha Not tainted 5.16.0+ #48 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIO4 RIP: 0010:__page_table_check_zero+0x159/0x1a0 Call Trace: free_pcp_prepare+0x3be/0xaa0 free_unref_page+0x1c/0x650 free_compound_page+0xec/0x130 free_transhuge_page+0x1be/0x260 __put_compound_page+0x90/0xd0 release_pages+0x54c/0x1060 __pagevec_release+0x7c/0x110 shmem_undo_range+0x85e/0x1250 ... The repro involved having a huge page that is split due to uprobe event temporarily replacing one of the pages in the huge page. Later the huge page was combined again, but the counters were off, as the PTE level was not properly updated. Make sure that when PMD is cleared and prior to freeing the level the PTEs are updated. Link: https://lkml.kernel.org/r/20220131203249.2832273-5-pasha.tatashin@soleen.com Fixes: df4e817b7108 ("mm: page table check") Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Thelen <gthelen@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Paul Turner <pjt@google.com> Cc: Wei Xu <weixugc@google.com> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-02-04mm/khugepaged: unify collapse pmd clear, flush and freePasha Tatashin1-16/+18
Unify the code that flushes, clears pmd entry, and frees the PTE table level into a new function collapse_and_free_pmd(). This cleanup is useful as in the next patch we will add another call to this function to iterate through PTE prior to freeing the level for page table check. Link: https://lkml.kernel.org/r/20220131203249.2832273-4-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Thelen <gthelen@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Paul Turner <pjt@google.com> Cc: Wei Xu <weixugc@google.com> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-12/+11
Merge misc updates from Andrew Morton: "146 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak, dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap, memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb, userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp, ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits) mm/damon: hide kernel pointer from tracepoint event mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging mm/damon/dbgfs: remove an unnecessary variable mm/damon: move the implementation of damon_insert_region to damon.h mm/damon: add access checking for hugetlb pages Docs/admin-guide/mm/damon/usage: update for schemes statistics mm/damon/dbgfs: support all DAMOS stats Docs/admin-guide/mm/damon/reclaim: document statistics parameters mm/damon/reclaim: provide reclamation statistics mm/damon/schemes: account how many times quota limit has exceeded mm/damon/schemes: account scheme actions that successfully applied mm/damon: remove a mistakenly added comment for a future feature Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning Docs/admin-guide/mm/damon/usage: remove redundant information Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks mm/damon: convert macro functions to static inline functions mm/damon: modify damon_rand() macro to static inline function mm/damon: move damon_rand() definition into damon.h ...
2022-01-15mm: fix some comment errorsQuanfa Fu1-1/+1
Link: https://lkml.kernel.org/r/20211101040208.460810-1-fuqf0919@gmail.com Signed-off-by: Quanfa Fu <fuqf0919@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15mm/vmstat: add events for THP max_ptes_* exceedsYang Yang1-0/+7
There are interfaces to adjust max_ptes_none, max_ptes_swap, max_ptes_shared values, see /sys/kernel/mm/transparent_hugepage/khugepaged/. But system administrator may not know which value is the best. So Add those events to support adjusting max_ptes_* to suitable values. For example, if default max_ptes_swap value causes too much failures, and system uses zram whose IO is fast, administrator could increase max_ptes_swap until THP_SCAN_EXCEED_SWAP_PTE not increase anymore. Link: https://lkml.kernel.org/r/20211225094036.574157-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Saravanan D <saravanand@fb.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15mm: remove last argument of reuse_swap_page()Matthew Wilcox (Oracle)1-1/+1
None of the callers care about the total_map_swapcount() any more. Link: https://lkml.kernel.org/r/20211220205943.456187-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15mm: ptep_clear() page table helperPasha Tatashin1-10/+2
We have ptep_get_and_clear() and ptep_get_and_clear_full() helpers to clear PTE from user page tables, but there is no variant for simple clear of a present PTE from user page tables without using a low level pte_clear() which can be either native or para-virtualised. Add a new ptep_clear() that can be used in common code to clear PTEs from page table. We will need this call later in order to add a hook for page table check. Link: https://lkml.kernel.org/r/20211221154650.1047963-3-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Xu <weixugc@google.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-08mm: Use multi-index entries in the page cacheMatthew Wilcox (Oracle)1-1/+11
We currently store large folios as 2^N consecutive entries. While this consumes rather more memory than necessary, it also turns out to be buggy. A writeback operation which starts within a tail page of a dirty folio will not write back the folio as the xarray's dirty bit is only set on the head index. With multi-index entries, the dirty bit will be found no matter where in the folio the operation starts. This does end up simplifying the page cache slightly, although not as much as I had hoped. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2021-11-06Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-2/+8
Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ...
2021-11-06mm: khugepaged: recalculate min_free_kbytes after stopping khugepagedLiangcai Fan1-2/+8
When initializing transparent huge pages, min_free_kbytes would be calculated according to what khugepaged expected. So when transparent huge pages get disabled, min_free_kbytes should be recalculated instead of the higher value set by khugepaged. Link: https://lkml.kernel.org/r/1633937809-16558-1-git-send-email-liangcaifan19@gmail.com Signed-off-by: Liangcai Fan <liangcaifan19@gmail.com> Signed-off-by: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-01Merge tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecacheLinus Torvalds1-4/+4
Pull memory folios from Matthew Wilcox: "Add memory folios, a new type to represent either order-0 pages or the head page of a compound page. This should be enough infrastructure to support filesystems converting from pages to folios. The point of all this churn is to allow filesystems and the page cache to manage memory in larger chunks than PAGE_SIZE. The original plan was to use compound pages like THP does, but I ran into problems with some functions expecting only a head page while others expect the precise page containing a particular byte. The folio type allows a function to declare that it's expecting only a head page. Almost incidentally, this allows us to remove various calls to VM_BUG_ON(PageTail(page)) and compound_head(). This converts just parts of the core MM and the page cache. For 5.17, we intend to convert various filesystems (XFS and AFS are ready; other filesystems may make it) and also convert more of the MM and page cache to folios. For 5.18, multi-page folios should be ready. The multi-page folios offer some improvement to some workloads. The 80% win is real, but appears to be an artificial benchmark (postgres startup, which isn't a serious workload). Real workloads (eg building the kernel, running postgres in a steady state, etc) seem to benefit between 0-10%. I haven't heard of any performance losses as a result of this series. Nobody has done any serious performance tuning; I imagine that tweaking the readahead algorithm could provide some more interesting wins. There are also other places where we could choose to create large folios and currently do not, such as writes that are larger than PAGE_SIZE. I'd like to thank all my reviewers who've offered review/ack tags: Christoph Hellwig, David Howells, Jan Kara, Jeff Layton, Johannes Weiner, Kirill A. Shutemov, Michal Hocko, Mike Rapoport, Vlastimil Babka, William Kucharski, Yu Zhao and Zi Yan. I'd also like to thank those who gave feedback I incorporated but haven't offered up review tags for this part of the series: Nick Piggin, Mel Gorman, Ming Lei, Darrick Wong, Ted Ts'o, John Hubbard, Hugh Dickins, and probably a few others who I forget" * tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecache: (90 commits) mm/writeback: Add folio_write_one mm/filemap: Add FGP_STABLE mm/filemap: Add filemap_get_folio mm/filemap: Convert mapping_get_entry to return a folio mm/filemap: Add filemap_add_folio() mm/filemap: Add filemap_alloc_folio mm/page_alloc: Add folio allocation functions mm/lru: Add folio_add_lru() mm/lru: Convert __pagevec_lru_add_fn to take a folio mm: Add folio_evictable() mm/workingset: Convert workingset_refault() to take a folio mm/filemap: Add readahead_folio() mm/filemap: Add folio_mkwrite_check_truncate() mm/filemap: Add i_blocks_per_folio() mm/writeback: Add folio_redirty_for_writepage() mm/writeback: Add folio_account_redirty() mm/writeback: Add folio_clear_dirty_for_io() mm/writeback: Add folio_cancel_dirty() mm/writeback: Add folio_account_cleaned() mm/writeback: Add filemap_dirty_folio() ...
2021-10-28mm: khugepaged: skip huge page collapse for special filesYang Shi1-8/+11
The read-only THP for filesystems will collapse THP for files opened readonly and mapped with VM_EXEC. The intended usecase is to avoid TLB misses for large text segments. But it doesn't restrict the file types so a THP could be collapsed for a non-regular file, for example, block device, if it is opened readonly and mapped with EXEC permission. This may cause bugs, like [1] and [2]. This is definitely not the intended usecase, so just collapse THP for regular files in order to close the attack surface. [shy828301@gmail.com: fix vm_file check [3]] Link: https://lore.kernel.org/lkml/CACkBjsYwLYLRmX8GpsDpMthagWOjWWrNxqY6ZLNQVr6yx+f5vA@mail.gmail.com/ [1] Link: https://lore.kernel.org/linux-mm/000000000000c6a82505ce284e4c@google.com/ [2] Link: https://lkml.kernel.org/r/CAHbLzkqTW9U3VvTu1Ki5v_cLRC9gHW+znBukg_ycergE0JWj-A@mail.gmail.com [3] Link: https://lkml.kernel.org/r/20211027195221.3825-1-shy828301@gmail.com Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Yang Shi <shy828301@gmail.com> Reported-by: Hao Sun <sunhao.th@gmail.com> Reported-by: syzbot+aae069be1de40fb11825@syzkaller.appspotmail.com Cc: Matthew Wilcox <willy@infradead.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Song Liu <songliubraving@fb.com> Cc: Andrea Righi <andrea.righi@canonical.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-10-28mm, thp: bail out early in collapse_file for writeback pageRongwei Wang1-1/+6
Currently collapse_file does not explicitly check PG_writeback, instead, page_has_private and try_to_release_page are used to filter writeback pages. This does not work for xfs with blocksize equal to or larger than pagesize, because in such case xfs has no page->private. This makes collapse_file bail out early for writeback page. Otherwise, xfs end_page_writeback will panic as follows. page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32 aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:"libtest.so" flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback) raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8 raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000 page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u)) page->mem_cgroup:ffff0000c3e9a000 ------------[ cut here ]------------ kernel BUG at include/linux/mm.h:1212! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: BUG: Bad page state in process khugepaged pfn:84ef32 xfs(E) page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32 libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ... CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ... pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--) Call trace: end_page_writeback+0x1c0/0x214 iomap_finish_page_writeback+0x13c/0x204 iomap_finish_ioend+0xe8/0x19c iomap_writepage_end_bio+0x38/0x50 bio_endio+0x168/0x1ec blk_update_request+0x278/0x3f0 blk_mq_end_request+0x34/0x15c virtblk_request_done+0x38/0x74 [virtio_blk] blk_done_softirq+0xc4/0x110 __do_softirq+0x128/0x38c __irq_exit_rcu+0x118/0x150 irq_exit+0x1c/0x30 __handle_domain_irq+0x8c/0xf0 gic_handle_irq+0x84/0x108 el1_irq+0xcc/0x180 arch_cpu_idle+0x18/0x40 default_idle_call+0x4c/0x1a0 cpuidle_idle_call+0x168/0x1e0 do_idle+0xb4/0x104 cpu_startup_entry+0x30/0x9c secondary_start_kernel+0x104/0x180 Code: d4210000 b0006161 910c8021 94013f4d (d4210000) ---[ end trace 4a88c6a074082f8c ]--- Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt Link: https://lkml.kernel.org/r/20211022023052.33114-1-rongwei.wang@linux.alibaba.com Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com> Signed-off-by: Xu Yu <xuyu@linux.alibaba.com> Suggested-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Yang Shi <shy828301@gmail.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Song Liu <song@kernel.org> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-27mm/memcg: Convert mem_cgroup_uncharge() to take a folioMatthew Wilcox (Oracle)1-2/+2
Convert all the callers to call page_folio(). Most of them were already using a head page, but a few of them I can't prove were, so this may actually fix a bug. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-27mm/memcg: Convert mem_cgroup_charge() to take a folioMatthew Wilcox (Oracle)1-2/+2
Convert all callers of mem_cgroup_charge() to call page_folio() on the page they're currently passing in. Many of them will be converted to use folios themselves soon. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-03huge tmpfs: SGP_NOALLOC to stop collapse_file() on raceHugh Dickins1-1/+1
khugepaged's collapse_file() currently uses SGP_NOHUGE to tell shmem_getpage() not to try allocating a huge page, in the very unlikely event that a racing hole-punch removes the swapped or fallocated page as soon as i_pages lock is dropped. We want to consolidate shmem's huge decisions, removing SGP_HUGE and SGP_NOHUGE; but cannot quite persuade ourselves that it's okay to regress the protection in this case - Yang Shi points out that the huge page would remain indefinitely, charged to root instead of the intended memcg. collapse_file() should not even allocate a small page in this case: why proceed if someone is punching a hole? SGP_READ is almost the right flag here, except that it optimizes away from a fallocated page, with NULL to tell caller to fill with zeroes (like a hole); whereas collapse_file()'s sequence relies on using a cache page. Add SGP_NOALLOC just for this. There are too many consecutive "if (page"s there in shmem_getpage_gfp(): group it better; and fix the outdated "bring it back from swap" comment. Link: https://lkml.kernel.org/r/1355343b-acf-4653-ef79-6aee40214ac5@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Rik van Riel <riel@surriel.com> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30mm, thp: relax the VM_DENYWRITE constraint on file-backed THPsCollin Fijalkovich1-1/+15
Transparent huge pages are supported for read-only non-shmem files, but are only used for vmas with VM_DENYWRITE. This condition ensures that file THPs are protected from writes while an application is running (ETXTBSY). Any existing file THPs are then dropped from the page cache when a file is opened for write in do_dentry_open(). Since sys_mmap ignores MAP_DENYWRITE, this constrains the use of file THPs to vmas produced by execve(). Systems that make heavy use of shared libraries (e.g. Android) are unable to apply VM_DENYWRITE through the dynamic linker, preventing them from benefiting from the resultant reduced contention on the TLB. This patch reduces the constraint on file THPs allowing use with any executable mapping from a file not opened for write (see inode_is_open_for_write()). It also introduces additional conditions to ensure that files opened for write will never be backed by file THPs. Restricting the use of THPs to executable mappings eliminates the risk that a read-only file later opened for write would encounter significant latencies due to page cache truncation. The ld linker flag '-z max-page-size=(hugepage size)' can be used to produce executables with the necessary layout. The dynamic linker must map these file's segments at a hugepage size aligned vma for the mapping to be backed with THPs. Comparison of the performance characteristics of 4KB and 2MB-backed libraries follows; the Android dex2oat tool was used to AOT compile an example application on a single ARM core. 4KB Pages: ========== count event_name # count / runtime 598,995,035,942 cpu-cycles # 1.800861 GHz 81,195,620,851 raw-stall-frontend # 244.112 M/sec 347,754,466,597 iTLB-loads # 1.046 G/sec 2,970,248,900 iTLB-load-misses # 0.854122% miss rate Total test time: 332.854998 seconds. 2MB Pages: ========== count event_name # count / runtime 592,872,663,047 cpu-cycles # 1.800358 GHz 76,485,624,143 raw-stall-frontend # 232.261 M/sec 350,478,413,710 iTLB-loads # 1.064 G/sec 803,233,322 iTLB-load-misses # 0.229182% miss rate Total test time: 329.826087 seconds A check of /proc/$(pidof dex2oat64)/smaps shows THPs in use: /apex/com.android.art/lib64/libart.so FilePmdMapped: 4096 kB /apex/com.android.art/lib64/libart-compiler.so FilePmdMapped: 2048 kB Link: https://lkml.kernel.org/r/20210406000930.3455850-1-cfijalkovich@google.com Signed-off-by: Collin Fijalkovich <cfijalkovich@google.com> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Acked-by: Song Liu <song@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Hridya Valsaraju <hridya@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Tim Murray <timmurray@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30mm/huge_memory.c: add missing read-only THP checking in ↵Miaohe Lin1-3/+1
transparent_hugepage_enabled() Since commit 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS"), read-only THP file mapping is supported. But it forgot to add checking for it in transparent_hugepage_enabled(). To fix it, we add checking for read-only THP file mapping and also introduce helper transhuge_vma_enabled() to check whether thp is enabled for specified vma to reduce duplicated code. We rename transparent_hugepage_enabled to transparent_hugepage_active to make the code easier to follow as suggested by David Hildenbrand. [linmiaohe@huawei.com: define transhuge_vma_enabled next to transhuge_vma_suitable] Link: https://lkml.kernel.org/r/20210514093007.4117906-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210511134857.1581273-4-linmiaohe@huawei.com Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Rik van Riel <riel@surriel.com> Cc: Song Liu <songliubraving@fb.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07mm: fix typos in commentsIngo Molnar1-1/+1
Fix ~94 single-word typos in locking code comments, plus a few very obvious grammar mistakes. Link: https://lkml.kernel.org/r/20210322212624.GA1963421@gmail.com Link: https://lore.kernel.org/r/20210322205203.GB1959563@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05mm/vmscan: replace implicit RECLAIM_ZONE checks with explicit checksDave Hansen1-1/+1
RECLAIM_ZONE was assumed to be unused because it was never explicitly used in the kernel. However, there were a number of places where it was checked implicitly by checking 'node_reclaim_mode' for a zero value. These zero checks are not great because it is not obvious what a zero mode *means* in the code. Replace them with a helper which makes it more obvious: node_reclaim_enabled(). This helper also provides a handy place to explicitly check the RECLAIM_ZONE bit itself. Check it explicitly there to make it more obvious where the bit can affect behavior. This should have no functional impact. Link: https://lkml.kernel.org/r/20210219172559.BF589C44@viggo.jf.intel.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Ben Widawsky <ben.widawsky@intel.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: "Tobin C. Harding" <tobin@kernel.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Qian Cai <cai@lca.pw> Cc: Daniel Wagner <dwagner@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05khugepaged: remove meaningless !pte_present() check in khugepaged_scan_pmd()Miaohe Lin1-4/+0
We know it must meet the !is_swap_pte() and !pte_none() condition if we reach here. Since !is_swap_pte() indicates pte_none() or pte_present() is met, it's guaranteed that pte must be present here. Link: https://lkml.kernel.org/r/20210325135647.64106-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05khugepaged: remove unnecessary out label in collapse_huge_page()Miaohe Lin1-5/+3
The out label here is unneeded because it just goes to out_up_write label. Remove it to make code more concise. Link: https://lkml.kernel.org/r/20210325135647.64106-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05khugepaged: use helper function range_in_vma() in collapse_pte_mapped_thp()Miaohe Lin1-1/+1
Patch series "Cleanup for khugepaged". This series contains cleanups to remove unnecessary out label and meaningless !pte_present() check. Also use helper function to simplify the code. More details can be found in the respective changelogs. This patch (of 3): We could use helper function range_in_vma() to check whether the desired range is inside the vma to simplify the code. Link: https://lkml.kernel.org/r/20210325135647.64106-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210325135647.64106-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05mm/khugepaged.c: replace barrier() with READ_ONCE() for a selective variableYanfei Xu1-3/+1
READ_ONCE() is more selective and lightweight. It is more appropriate that using a READ_ONCE() for the certain variable to prevent the compiler from reordering. Link: https://lkml.kernel.org/r/20210323092730.247583-1-yanfei.xu@windriver.com Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05khugepaged: fix wrong result value for trace_mm_collapse_huge_page_isolate()Miaohe Lin1-9/+9
In writable and !referenced case, the result value should be SCAN_LACK_REFERENCED_PAGE for trace_mm_collapse_huge_page_isolate() instead of default 0 (SCAN_FAIL) here. Link: https://lkml.kernel.org/r/20210306032947.35921-5-linmiaohe@huawei.com Fixes: 7d2eba0557c1 ("mm: add tracepoint for scanning pages") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05khugepaged: use helper khugepaged_test_exit() in __khugepaged_enter()Miaohe Lin1-1/+1
Commit 4d45e75a9955 ("mm: remove the now-unnecessary mmget_still_valid() hack") have made khugepaged_test_exit() suitable for check mm->mm_users against 0. Use this helper here. Link: https://lkml.kernel.org/r/20210306032947.35921-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05khugepaged: reuse the smp_wmb() inside __SetPageUptodate()Miaohe Lin1-7/+6
smp_wmb() is needed to avoid the copy_huge_page writes to become visible after the set_pmd_at() write here. But we can reuse the smp_wmb() inside __SetPageUptodate() to remove this redundant one. Link: https://lkml.kernel.org/r/20210306032947.35921-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05khugepaged: remove unneeded return value of ↵Miaohe Lin1-6/+4
khugepaged_collapse_pte_mapped_thps() Patch series "Cleanup and fixup for khugepaged", v2. This series contains cleanups to remove unneeded return value, use helper function and so on. And there is one fix to correct the wrong result value for trace_mm_collapse_huge_page_isolate(). This patch (of 4): The return value of khugepaged_collapse_pte_mapped_thps() is never checked since it's introduced. We should remove such unneeded return value. Link: https://lkml.kernel.org/r/20210306032947.35921-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210306032947.35921-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26mm,thp,shmem: make khugepaged obey tmpfs mount flagsRik van Riel1-6/+16
Currently if thp enabled=[madvise], mounting a tmpfs filesystem with huge=always and mmapping files from that tmpfs does not result in khugepaged collapsing those mappings, despite the mount flag indicating that it should. Fix that by breaking up the blocks of tests in hugepage_vma_check a little bit, and testing things in the correct order. Link: https://lkml.kernel.org/r/20201124194925.623931-4-riel@surriel.com Fixes: c2231020ea7b ("mm: thp: register mm for khugepaged when merging vma for shmem") Signed-off-by: Rik van Riel <riel@surriel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xu Yu <xuyu@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24mm: memcontrol: convert NR_SHMEM_THPS account to pagesMuchun Song1-1/+1
Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_SHMEM_THPS account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-5-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: NeilBrown <neilb@suse.de> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Rafael. J. Wysocki <rafael@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <guro@fb.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24mm: memcontrol: convert NR_FILE_THPS account to pagesMuchun Song1-1/+3
Currently we use struct per_cpu_nodestat to cache the vmstat counters, which leads to inaccurate statistics especially THP vmstat counters. In the systems with if hundreds of processors it can be GBs of memory. For example, for a 96 CPUs system, the threshold is the maximum number of 125. And the per cpu counters can cache 23.4375 GB in total. The THP page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like sensible. Although every THP stats update overflows the per-cpu counter, resorting to atomic global updates. But it can make the statistics more accuracy for the THP vmstat counters. So we convert the NR_FILE_THPS account to pages. This patch is consistent with 8f182270dfec ("mm/swap.c: flush lru pvecs on compound page arrival"). Doing this also can make the unit of vmstat counters more unified. Finally, the unit of the vmstat counters are pages, kB and bytes. The B/KB suffix can tell us that the unit is bytes or kB. The rest which is without suffix are pages. Link: https://lkml.kernel.org/r/20201228164110.2838-4-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.com> Cc: NeilBrown <neilb@suse.de> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Rafael. J. Wysocki <rafael@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Roman Gushchin <guro@fb.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-21mm: Avoid modifying vmf.address in __collapse_huge_page_swapin()Will Deacon1-19/+18
In preparation for const-ifying the anonymous struct field of 'struct vm_fault', rework __collapse_huge_page_swapin() to avoid continuously updating vmf.address and instead populate a new 'struct vm_fault' on the stack for each page being processed. Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-12-15mm: fix some spelling mistakes in commentsHaitao Shi1-1/+1
Fix some spelling mistakes in comments: udpate ==> update succesful ==> successful exmaple ==> example unneccessary ==> unnecessary stoping ==> stopping uknown ==> unknown Link: https://lkml.kernel.org/r/20201127011747.86005-1-shihaitao1@huawei.com Signed-off-by: Haitao Shi <shihaitao1@huawei.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15mm: cleanup kstrto*() usageAlexey Dobriyan1-9/+9
Range checks can folded into proper conversion function. kstrto*() exist for all arithmetic types. Link: https://lkml.kernel.org/r/20201122123759.GC92364@localhost.localdomain Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15mm: use sysfs_emit for struct kobject * usesJoe Perches1-11/+11
Patch series "mm: Convert sysfs sprintf family to sysfs_emit", v2. Use the new sysfs_emit family and not the sprintf family. This patch (of 5): Use the sysfs_emit function instead of the sprintf family. Done with cocci script as in commit 3c6bff3cf988 ("RDMA: Convert sysfs kobject * show functions to use sysfs_emit()") Link: https://lkml.kernel.org/r/cover.1605376435.git.joe@perches.com Link: https://lkml.kernel.org/r/9c249215bad6df616ba0410ad980042694970c1b.1605376435.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15khugepaged: add parameter explanations for kernel-doc markupAlex Shi1-1/+13
Add missed parameter explanation for some kernel-doc warnings: mm/khugepaged.c:102: warning: Function parameter or member 'nr_pte_mapped_thp' not described in 'mm_slot' mm/khugepaged.c:102: warning: Function parameter or member 'pte_mapped_thp' not described in 'mm_slot' mm/khugepaged.c:1424: warning: Function parameter or member 'mm' not described in 'collapse_pte_mapped_thp' mm/khugepaged.c:1424: warning: Function parameter or member 'addr' not described in 'collapse_pte_mapped_thp' mm/khugepaged.c:1626: warning: Function parameter or member 'mm' not described in 'collapse_file' mm/khugepaged.c:1626: warning: Function parameter or member 'file' not described in 'collapse_file' mm/khugepaged.c:1626: warning: Function parameter or member 'start' not described in 'collapse_file' mm/khugepaged.c:1626: warning: Function parameter or member 'hpage' not described in 'collapse_file' mm/khugepaged.c:1626: warning: Function parameter or member 'node' not described in 'collapse_file' Link: https://lkml.kernel.org/r/1605597325-25284-1-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15mm: memcontrol: add file_thp, shmem_thp to memory.statJohannes Weiner1-2/+2
As huge page usage in the page cache and for shmem files proliferates in our production environment, the performance monitoring team has asked for per-cgroup stats on those pages. We already track and export anon_thp per cgroup. We already track file THP and shmem THP per node, so making them per-cgroup is only a matter of switching from node to lruvec counters. All callsites are in places where the pages are charged and locked, so page->memcg is stable. [hannes@cmpxchg.org: add documentation] Link: https://lkml.kernel.org/r/20201026174029.GC548555@cmpxchg.org Link: https://lkml.kernel.org/r/20201022151844.489337-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@surriel.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>