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2024-06-15mm: fix possible OOB in numa_rebuild_large_mapping()Kefeng Wang
The large folio is mapped with folio size(not greater PMD_SIZE) aligned virtual address during the pagefault, ie, 'addr = ALIGN_DOWN(vmf->address, nr_pages * PAGE_SIZE)' in do_anonymous_page(). But after the mremap(), the virtual address only requires PAGE_SIZE alignment. Also pte is moved to new in move_page_tables(), then traversal of the new pte in the numa_rebuild_large_mapping() could hit the following issue, Unable to handle kernel paging request at virtual address 00000a80c021a788 Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00002040341a6000 [00000a80c021a788] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 0000000096000004 [#1] SMP ... CPU: 76 PID: 15187 Comm: git Kdump: loaded Tainted: G W 6.10.0-rc2+ #209 Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 1.79 08/21/2021 pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : numa_rebuild_large_mapping+0x338/0x638 lr : numa_rebuild_large_mapping+0x320/0x638 sp : ffff8000b41c3b00 x29: ffff8000b41c3b30 x28: ffff8000812a0000 x27: 00000000000a8000 x26: 00000000000000a8 x25: 0010000000000001 x24: ffff20401c7170f0 x23: 0000ffff33a1e000 x22: 0000ffff33a76000 x21: ffff20400869eca0 x20: 0000ffff33976000 x19: 00000000000000a8 x18: ffffffffffffffff x17: 0000000000000000 x16: 0000000000000020 x15: ffff8000b41c36a8 x14: 0000000000000000 x13: 205d373831353154 x12: 5b5d333331363732 x11: 000000000011ff78 x10: 000000000011ff10 x9 : ffff800080273f30 x8 : 000000320400869e x7 : c0000000ffffd87f x6 : 00000000001e6ba8 x5 : ffff206f3fb5af88 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : fffffdffc0000000 x0 : 00000a80c021a780 Call trace: numa_rebuild_large_mapping+0x338/0x638 do_numa_page+0x3e4/0x4e0 handle_pte_fault+0x1bc/0x238 __handle_mm_fault+0x20c/0x400 handle_mm_fault+0xa8/0x288 do_page_fault+0x124/0x498 do_translation_fault+0x54/0x80 do_mem_abort+0x4c/0xa8 el0_da+0x40/0x110 el0t_64_sync_handler+0xe4/0x158 el0t_64_sync+0x188/0x190 Fix it by making the start and end not only within the vma range, but also within the page table range. Link: https://lkml.kernel.org/r/20240612122822.4033433-1-wangkefeng.wang@huawei.com Fixes: d2136d749d76 ("mm: support multi-size THP numa balancing") Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-15Revert "mm: init_mlocked_on_free_v3"David Hildenbrand
There was insufficient review and no agreement that this is the right approach. There are serious flaws with the implementation that make processes using mlock() not even work with simple fork() [1] and we get reliable crashes when rebooting. Further, simply because we might be unmapping a single PTE of a large mlocked folio, we shouldn't zero out the whole folio. ... especially because the code can also *corrupt* urelated memory because kernel_init_pages(page, folio_nr_pages(folio)); Could end up writing outside of the actual folio if we work with a tail page. Let's revert it. Once there is agreement that this is the right approach, the issues were fixed and there was reasonable review and proper testing, we can consider it again. [1] https://lkml.kernel.org/r/4da9da2f-73e4-45fd-b62f-a8a513314057@redhat.com Link: https://lkml.kernel.org/r/20240605091710.38961-1-david@redhat.com Fixes: ba42b524a040 ("mm: init_mlocked_on_free_v3") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: David Wang <00107082@163.com> Closes: https://lore.kernel.org/lkml/20240528151340.4282-1-00107082@163.com/ Reported-by: Lance Yang <ioworker0@gmail.com> Closes: https://lkml.kernel.org/r/20240601140917.43562-1-ioworker0@gmail.com Acked-by: Lance Yang <ioworker0@gmail.com> Cc: York Jasper Niebuhr <yjnworkstation@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-22mm: simplify and improve print_vma_addr() outputLinus Torvalds
Use '%pD' to print out the filename, and print out the actual offset within the file too, rather than just what the virtual address of the mapping is (which doesn't tell you anything about any mapping offsets). Also, use the exact vma_lookup() instead of find_vma() - the latter looks up any vma _after_ the address, which is of questionable value (yes, maybe you fell off the beginning, but you'd be more likely to fall off the end). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-05-05mm: optimise vmf_anon_prepare() for VMAs without an anon_vmaMatthew Wilcox (Oracle)
If the mmap_lock can be taken for read, we can call __anon_vma_prepare() while holding it, saving ourselves a trip back through the fault handler. Link: https://lkml.kernel.org/r/20240426144506.1290619-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm: delay the check for a NULL anon_vmaMatthew Wilcox (Oracle)
Instead of checking the anon_vma early in the fault path where all page faults pay the cost, delay it until we know we're going to need the anon_vma to be filled in. This will have a slight negative effect on the first fault in an anonymous VMA, but it shortens every other page fault. It also makes the code slightly cleaner as the anon and file backed fault handling look more similar. The Intel kernel test bot reports a 3x improvement in vm-scalability throughput with the small-allocs-mt test. This is clearly an extreme situation that won't be replicated in any real-world workload, but it's a nice win. https://lore.kernel.org/all/202404261055.c5e24608-oliver.sang@intel.com/ Link: https://lkml.kernel.org/r/20240426144506.1290619-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm: simplify thp_vma_allowable_orderMatthew Wilcox
Combine the three boolean arguments into one flags argument for readability. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm: memory: check userfaultfd_wp() in vmf_orig_pte_uffd_wp()Kefeng Wang
Add userfaultfd_wp() check in vmf_orig_pte_uffd_wp() to avoid the unnecessary FAULT_FLAG_ORIG_PTE_VALID check/pte_marker_entry_uffd_wp() in most pagefault, note, the function vmf_orig_pte_uffd_wp() is not inlined in the two kernel versions, the difference is shown below, perf date, perf report -i perf.data.before | grep vmf 0.17% 0.13% lat_pagefault [kernel.kallsyms] [k] vmf_orig_pte_uffd_wp.part.0.isra.0 perf report -i perf.data.after | grep vmf lat_pagefault -W 5 -N 5 /tmp/XXX latency before after diff average(8 tests) 0.262675 0.2600375 -0.0026375 Although it's a small, but the uffd_wp is a new feature than previous kernel, when the vma is not registered with UFFD_WP, let's avoid to execute the new logical, also adding __always_inline attribute to vmf_orig_pte_uffd_wp(), which make set_pte_range() only check VM_UFFD_WP flags without the function call. In addition, directly call the vmf_orig_pte_uffd_wp() in do_anonymous_page() and set_pte_range() to save an uffd_wp variable. Link: https://lkml.kernel.org/r/20240422030039.3293568-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm/memory: add any_dirty optional pointer to folio_pte_batch()Lance Yang
This commit adds the any_dirty pointer as an optional parameter to folio_pte_batch() function. By using both the any_young and any_dirty pointers, madvise_free can make smarter decisions about whether to clear the PTEs when marking large folios as lazyfree. Link: https://lkml.kernel.org/r/20240418134435.6092-4-ioworker0@gmail.com Signed-off-by: Lance Yang <ioworker0@gmail.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Jeff Xie <xiehuan09@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm: move mm counter updating out of set_pte_range()Kefeng Wang
Patch series "mm: batch mm counter updating in filemap_map_pages()", v3. Let's batch mm counter updating to accelerate filemap_map_pages(). This patch (of 2): In order to support batch mm counter updating in filemap_map_pages(), move mm counter updating out of set_pte_range(), the folios are file from filemap, and distinguish folios by vmf->flags and vma->vm_flags from another caller finish_fault(). Link: https://lkml.kernel.org/r/20240412064751.119015-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20240412064751.119015-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm: add per-order mTHP anon_fault_alloc and anon_fault_fallback countersBarry Song
Patch series "mm: add per-order mTHP alloc and swpout counters", v6. The patchset introduces a framework to facilitate mTHP counters, starting with the allocation and swap-out counters. Currently, only four new nodes are appended to the stats directory for each mTHP size. /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats anon_fault_alloc anon_fault_fallback anon_fault_fallback_charge anon_swpout anon_swpout_fallback These nodes are crucial for us to monitor the fragmentation levels of both the buddy system and the swap partitions. In the future, we may consider adding additional nodes for further insights. This patch (of 4): Profiling a system blindly with mTHP has become challenging due to the lack of visibility into its operations. Presenting the success rate of mTHP allocations appears to be pressing need. Recently, I've been experiencing significant difficulty debugging performance improvements and regressions without these figures. It's crucial for us to understand the true effectiveness of mTHP in real-world scenarios, especially in systems with fragmented memory. This patch establishes the framework for per-order mTHP counters. It begins by introducing the anon_fault_alloc and anon_fault_fallback counters. Additionally, to maintain consistency with thp_fault_fallback_charge in /proc/vmstat, this patch also tracks anon_fault_fallback_charge when mem_cgroup_charge fails for mTHP. Incorporating additional counters should now be straightforward as well. Link: https://lkml.kernel.org/r/20240412114858.407208-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240412114858.407208-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Chris Li <chrisl@kernel.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm/memory: use folio_mapcount() in zap_present_folio_ptes()David Hildenbrand
We want to limit the use of page_mapcount() to the places where it is absolutely necessary. In zap_present_folio_ptes(), let's simply check the folio mapcount(). If there is some issue, it will underflow at some point either way when unmapping. As indicated already in commit 10ebac4f95e7 ("mm/memory: optimize unmap/zap with PTE-mapped THP"), we already documented "If we ever have a cheap folio_mapcount(), we might just want to check for underflows there.". There is no change for small folios. For large folios, we'll now catch more underflows when batch-unmapping, because instead of only testing the mapcount of the first subpage, we'll test if the folio mapcount underflows. Link: https://lkml.kernel.org/r/20240409192301.907377-8-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Chris Zankel <chris@zankel.net> Cc: Hugh Dickins <hughd@google.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Richard Chang <richardycc@google.com> Cc: Rich Felker <dalias@libc.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm: follow_pte() improvementsDavid Hildenbrand
follow_pte() is now our main function to lookup PTEs in VM_PFNMAP/VM_IO VMAs. Let's perform some more sanity checks to make this exported function harder to abuse. Further, extend the doc a bit, it still focuses on the KVM use case with MMU notifiers. Drop the KVM+follow_pfn() comment, follow_pfn() is no more, and we have other users nowadays. Also extend the doc regarding refcounted pages and the interaction with MMU notifiers. KVM is one example that uses MMU notifiers and can deal with refcounted pages properly. VFIO is one example that doesn't use MMU notifiers, and to prevent use-after-free, rejects refcounted pages: pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)). Protection changes are less of a concern for users like VFIO: the behavior is similar to longterm-pinning a page, and getting the PTE protection changed afterwards. The primary concern with refcounted pages is use-after-free, which callers should be aware of. Link: https://lkml.kernel.org/r/20240410155527.474777-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Fei Li <fei1.li@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Yonghua Huang <yonghua.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm: pass VMA instead of MM to follow_pte()David Hildenbrand
... and centralize the VM_IO/VM_PFNMAP sanity check in there. We'll now also perform these sanity checks for direct follow_pte() invocations. For generic_access_phys(), we might now check multiple times: nothing to worry about, really. Link: https://lkml.kernel.org/r/20240410155527.474777-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Sean Christopherson <seanjc@google.com> [KVM] Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Fei Li <fei1.li@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Yonghua Huang <yonghua.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: madvise: avoid split during MADV_PAGEOUT and MADV_COLDRyan Roberts
Rework madvise_cold_or_pageout_pte_range() to avoid splitting any large folio that is fully and contiguously mapped in the pageout/cold vm range. This change means that large folios will be maintained all the way to swap storage. This both improves performance during swap-out, by eliding the cost of splitting the folio, and sets us up nicely for maintaining the large folio when it is swapped back in (to be covered in a separate series). Folios that are not fully mapped in the target range are still split, but note that behavior is changed so that if the split fails for any reason (folio locked, shared, etc) we now leave it as is and move to the next pte in the range and continue work on the proceeding folios. Previously any failure of this sort would cause the entire operation to give up and no folios mapped at higher addresses were paged out or made cold. Given large folios are becoming more common, this old behavior would have likely lead to wasted opportunities. While we are at it, change the code that clears young from the ptes to use ptep_test_and_clear_young(), via the new mkold_ptes() batch helper function. This is more efficent than get_and_clear/modify/set, especially for contpte mappings on arm64, where the old approach would require unfolding/refolding and the new approach can be done in place. Link: https://lkml.kernel.org/r/20240408183946.2991168-8-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Chris Li <chrisl@kernel.org> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: swap: free_swap_and_cache_nr() as batched free_swap_and_cache()Ryan Roberts
Now that we no longer have a convenient flag in the cluster to determine if a folio is large, free_swap_and_cache() will take a reference and lock a large folio much more often, which could lead to contention and (e.g.) failure to split large folios, etc. Let's solve that problem by batch freeing swap and cache with a new function, free_swap_and_cache_nr(), to free a contiguous range of swap entries together. This allows us to first drop a reference to each swap slot before we try to release the cache folio. This means we only try to release the folio once, only taking the reference and lock once - much better than the previous 512 times for the 2M THP case. Contiguous swap entries are gathered in zap_pte_range() and madvise_free_pte_range() in a similar way to how present ptes are already gathered in zap_pte_range(). While we are at it, let's simplify by converting the return type of both functions to void. The return value was used only by zap_pte_range() to print a bad pte, and was ignored by everyone else, so the extra reporting wasn't exactly guaranteed. We will still get the warning with most of the information from get_swap_device(). With the batch version, we wouldn't know which pte was bad anyway so could print the wrong one. [ryan.roberts@arm.com: fix a build warning on parisc] Link: https://lkml.kernel.org/r/20240409111840.3173122-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20240408183946.2991168-3-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: support multi-size THP numa balancingBaolin Wang
Now the anonymous page allocation already supports multi-size THP (mTHP), but the numa balancing still prohibits mTHP migration even though it is an exclusive mapping, which is unreasonable. Allow scanning mTHP: Commit 859d4adc3415 ("mm: numa: do not trap faults on shared data section pages") skips shared CoW pages' NUMA page migration to avoid shared data segment migration. In addition, commit 80d47f5de5e3 ("mm: don't try to NUMA-migrate COW pages that have other uses") change to use page_count() to avoid GUP pages migration, that will also skip the mTHP numa scanning. Theoretically, we can use folio_maybe_dma_pinned() to detect the GUP issue, although there is still a GUP race, the issue seems to have been resolved by commit 80d47f5de5e3. Meanwhile, use the folio_likely_mapped_shared() to skip shared CoW pages though this is not a precise sharers count. To check if the folio is shared, ideally we want to make sure every page is mapped to the same process, but doing that seems expensive and using the estimated mapcount seems can work when running autonuma benchmark. Allow migrating mTHP: As mentioned in the previous thread[1], large folios (including THP) are more susceptible to false sharing issues among threads than 4K base page, leading to pages ping-pong back and forth during numa balancing, which is currently not easy to resolve. Therefore, as a start to support mTHP numa balancing, we can follow the PMD mapped THP's strategy, that means we can reuse the 2-stage filter in should_numa_migrate_memory() to check if the mTHP is being heavily contended among threads (through checking the CPU id and pid of the last access) to avoid false sharing at some degree. Thus, we can restore all PTE maps upon the first hint page fault of a large folio to follow the PMD mapped THP's strategy. In the future, we can continue to optimize the NUMA balancing algorithm to avoid the false sharing issue with large folios as much as possible. Performance data: Machine environment: 2 nodes, 128 cores Intel(R) Xeon(R) Platinum Base: 2024-03-25 mm-unstable branch Enable mTHP to run autonuma-benchmark mTHP:16K Base Patched numa01 numa01 224.70 143.48 numa01_THREAD_ALLOC numa01_THREAD_ALLOC 118.05 47.43 numa02 numa02 13.45 9.29 numa02_SMT numa02_SMT 14.80 7.50 mTHP:64K Base Patched numa01 numa01 216.15 114.40 numa01_THREAD_ALLOC numa01_THREAD_ALLOC 115.35 47.41 numa02 numa02 13.24 9.25 numa02_SMT numa02_SMT 14.67 7.34 mTHP:128K Base Patched numa01 numa01 205.13 144.45 numa01_THREAD_ALLOC numa01_THREAD_ALLOC 112.93 41.88 numa02 numa02 13.16 9.18 numa02_SMT numa02_SMT 14.81 7.49 [1] https://lore.kernel.org/all/20231117100745.fnpijbk4xgmals3k@techsingularity.net/ [baolin.wang@linux.alibaba.com: v3] Link: https://lkml.kernel.org/r/c33a5c0b0a0323b1f8ed53772f50501f4b196e25.1712132950.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/d28d276d599c26df7f38c9de8446f60e22dd1950.1711683069.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: factor out the numa mapping rebuilding into a new helperBaolin Wang
Patch series "support multi-size THP numa balancing", v2. This patchset tries to support mTHP numa balancing, as a simple solution to start, the NUMA balancing algorithm for mTHP will follow the THP strategy as the basic support. Please find details in each patch. This patch (of 2): To support large folio's numa balancing, factor out the numa mapping rebuilding into a new helper as a preparation. Link: https://lkml.kernel.org/r/cover.1712132950.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/cover.1711683069.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/8bc2586bdd8dbbe6d83c09b77b360ec8fcac3736.1711683069.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: alloc_anon_folio: avoid doing vma_thp_gfp_mask in fallback casesBarry Song
Fallback rates surpassing 90% have been observed on phones utilizing 64KiB CONT-PTE mTHP. In these scenarios, when one out of every 16 PTEs fails to allocate large folios, the remaining 15 PTEs fallback. Consequently, invoking vma_thp_gfp_mask seems redundant in such cases. Furthermore, abstaining from its use can also contribute to improved code readability. Link: https://lkml.kernel.org/r/20240329073750.20012-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Itaru Kitayama <itaru.kitayama@gmail.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: init_mlocked_on_free_v3York Jasper Niebuhr
Implements the "init_mlocked_on_free" boot option. When this boot option is enabled, any mlock'ed pages are zeroed on free. If the pages are munlock'ed beforehand, no initialization takes place. This boot option is meant to combat the performance hit of "init_on_free" as reported in commit 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options"). With "init_mlocked_on_free=1" only relevant data is freed while everything else is left untouched by the kernel. Correspondingly, this patch introduces no performance hit for unmapping non-mlock'ed memory. The unmapping overhead for purely mlocked memory was measured to be approximately 13%. Realistically, most systems mlock only a fraction of the total memory so the real-world system overhead should be close to zero. Optimally, userspace programs clear any key material or other confidential memory before exit and munlock the according memory regions. If a program crashes, userspace key managers fail to do this job. Accordingly, no munlock operations are performed so the data is caught and zeroed by the kernel. Should the program not crash, all memory will ideally be munlocked so no overhead is caused. CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON can be set to enable "init_mlocked_on_free" by default. Link: https://lkml.kernel.org/r/20240329145605.149917-1-yjnworkstation@gmail.com Signed-off-by: York Jasper Niebuhr <yjnworkstation@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: York Jasper Niebuhr <yjnworkstation@gmail.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: introduce vma_pgtable_walk_{begin|end}()Peter Xu
Introduce per-vma begin()/end() helpers for pgtable walks. This is a preparation work to merge hugetlb pgtable walkers with generic mm. The helpers need to be called before and after a pgtable walk, will start to be needed if the pgtable walker code supports hugetlb pages. It's a hook point for any type of VMA, but for now only hugetlb uses it to stablize the pgtable pages from getting away (due to possible pmd unsharing). Link: https://lkml.kernel.org/r/20240327152332.950956-5-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Muchun Song <muchun.song@linux.dev> Tested-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrew Jones <andrew.jones@linux.dev> Cc: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: move follow_phys to arch/x86/mm/pat/memtype.cChristoph Hellwig
follow_phys is only used by two callers in arch/x86/mm/pat/memtype.c. Move it there and hardcode the two arguments that get the same values passed by both callers. [david@redhat.com: conflict resolutions] Link: https://lkml.kernel.org/r/20240403212131.929421-4-david@redhat.com Link: https://lkml.kernel.org/r/20240324234542.2038726-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fei Li <fei1.li@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: remove follow_pfnChristoph Hellwig
Remove follow_pfn now that the last user is gone. Link: https://lkml.kernel.org/r/20240324234542.2038726-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fei Li <fei1.li@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: convert folio_estimated_sharers() to folio_likely_mapped_shared()David Hildenbrand
Callers of folio_estimated_sharers() only care about "mapped shared vs. mapped exclusively", not the exact estimate of sharers. Let's consolidate and unify the condition users are checking. While at it clarify the semantics and extend the discussion on the fuzziness. Use the "likely mapped shared" terminology to better express what the (adjusted) function actually checks. Whether a partially-mappable folio is more likely to not be partially mapped than partially mapped is debatable. In the future, we might be able to improve our estimate for partially-mappable folios, though. Note that we will now consistently detect "mapped shared" only if the first subpage is actually mapped multiple times. When the first subpage is not mapped, we will consistently detect it as "mapped exclusively". This change should currently only affect the usage in madvise_free_pte_range() and queue_folios_pte_range() for large folios: if the first page was already unmapped, we would have skipped the folio. [david@redhat.com: folio_likely_mapped_shared() kerneldoc fixup] Link: https://lkml.kernel.org/r/dd0ad9f2-2d7a-45f3-9ba3-979488c7dd27@redhat.com Link: https://lkml.kernel.org/r/20240227201548.857831-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Acked-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25arm64: mm: swap: support THP_SWAP on hardware with MTEBarry Song
Commit d0637c505f8a1 ("arm64: enable THP_SWAP for arm64") brings up THP_SWAP on ARM64, but it doesn't enable THP_SWP on hardware with MTE as the MTE code works with the assumption tags save/restore is always handling a folio with only one page. The limitation should be removed as more and more ARM64 SoCs have this feature. Co-existence of MTE and THP_SWAP becomes more and more important. This patch makes MTE tags saving support large folios, then we don't need to split large folios into base pages for swapping out on ARM64 SoCs with MTE any more. arch_prepare_to_swap() should take folio rather than page as parameter because we support THP swap-out as a whole. It saves tags for all pages in a large folio. As now we are restoring tags based-on folio, in arch_swap_restore(), we may increase some extra loops and early-exitings while refaulting a large folio which is still in swapcache in do_swap_page(). In case a large folio has nr pages, do_swap_page() will only set the PTE of the particular page which is causing the page fault. Thus do_swap_page() runs nr times, and each time, arch_swap_restore() will loop nr times for those subpages in the folio. So right now the algorithmic complexity becomes O(nr^2). Once we support mapping large folios in do_swap_page(), extra loops and early-exitings will decrease while not being completely removed as a large folio might get partially tagged in corner cases such as, 1. a large folio in swapcache can be partially unmapped, thus, MTE tags for the unmapped pages will be invalidated; 2. users might use mprotect() to set MTEs on a part of a large folio. arch_thp_swp_supported() is dropped since ARM64 MTE was the only one who needed it. Link: https://lkml.kernel.org/r/20240322114136.61386-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Steven Price <steven.price@arm.com> Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: "Mike Rapoport (IBM)" <rppt@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm/mempolicy: use numa_node_id() instead of cpu_to_node()Donet Tom
Patch series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy:, v4. This patchset is to optimize the cross-socket memory access with MPOL_PREFERRED_MANY policy. To test this patch we ran the following test on a 3 node system. Node 0 - 2GB - Tier 1 Node 1 - 11GB - Tier 1 Node 6 - 10GB - Tier 2 Below changes are made to memcached to set the memory policy, It select Node0 and Node1 as preferred nodes. #include <numaif.h> #include <numa.h> unsigned long nodemask; int ret; nodemask = 0x03; ret = set_mempolicy(MPOL_PREFERRED_MANY | MPOL_F_NUMA_BALANCING, &nodemask, 10); /* If MPOL_F_NUMA_BALANCING isn't supported, * fall back to MPOL_PREFERRED_MANY */ if (ret < 0 && errno == EINVAL){ printf("set mem policy normal\n"); ret = set_mempolicy(MPOL_PREFERRED_MANY, &nodemask, 10); } if (ret < 0) { perror("Failed to call set_mempolicy"); exit(-1); } Test Procedure: =============== 1. Make sure memory tiring and demotion are enabled. 2. Start memcached. # ./memcached -b 100000 -m 204800 -u root -c 1000000 -t 7 -d -s "/tmp/memcached.sock" 3. Run memtier_benchmark to store 3200000 keys. #./memtier_benchmark -S "/tmp/memcached.sock" --protocol=memcache_binary --threads=1 --pipeline=1 --ratio=1:0 --key-pattern=S:S --key-minimum=1 --key-maximum=3200000 -n allkeys -c 1 -R -x 1 -d 1024 4. Start a memory eater on node 0 and 1. This will demote all memcached pages to node 6. 5. Make sure all the memcached pages got demoted to lower tier by reading /proc/<memcaced PID>/numa_maps. # cat /proc/2771/numa_maps --- default anon=1009 dirty=1009 active=0 N6=1009 kernelpagesize_kB=64 default anon=1009 dirty=1009 active=0 N6=1009 kernelpagesize_kB=64 --- 6. Kill memory eater. 7. Read the pgpromote_success counter. 8. Start reading the keys by running memtier_benchmark. #./memtier_benchmark -S "/tmp/memcached.sock" --protocol=memcache_binary --pipeline=1 --distinct-client-seed --ratio=0:3 --key-pattern=R:R --key-minimum=1 --key-maximum=3200000 -n allkeys --threads=64 -c 1 -R -x 6 9. Read the pgpromote_success counter. Test Results: ============= Without Patch ------------------ 1. pgpromote_success before test Node 0: pgpromote_success 11 Node 1: pgpromote_success 140974 pgpromote_success after test Node 0: pgpromote_success 11 Node 1: pgpromote_success 140974 2. Memtier-benchmark result. AGGREGATED AVERAGE RESULTS (6 runs) ================================================================== Type Ops/sec Hits/sec Misses/sec Avg. Latency p50 Latency ------------------------------------------------------------------ Sets 0.00 --- --- --- --- Gets 305792.03 305791.93 0.10 0.18949 0.16700 Waits 0.00 --- --- --- --- Totals 305792.03 305791.93 0.10 0.18949 0.16700 ====================================== p99 Latency p99.9 Latency KB/sec ------------------------------------- --- --- 0.00 0.44700 1.71100 11542.69 --- --- --- 0.44700 1.71100 11542.69 With Patch --------------- 1. pgpromote_success before test Node 0: pgpromote_success 5 Node 1: pgpromote_success 89386 pgpromote_success after test Node 0: pgpromote_success 57895 Node 1: pgpromote_success 141463 2. Memtier-benchmark result. AGGREGATED AVERAGE RESULTS (6 runs) ==================================================================== Type Ops/sec Hits/sec Misses/sec Avg. Latency p50 Latency -------------------------------------------------------------------- Sets 0.00 --- --- --- --- Gets 521942.24 521942.07 0.17 0.11459 0.10300 Waits 0.00 --- --- --- --- Totals 521942.24 521942.07 0.17 0.11459 0.10300 ======================================= p99 Latency p99.9 Latency KB/sec --------------------------------------- --- --- 0.00 0.23100 0.31900 19701.68 --- --- --- 0.23100 0.31900 19701.68 Test Result Analysis: ===================== 1. With patch we could observe pages are getting promoted. 2. Memtier-benchmark results shows that, with the patch, performance has increased more than 50%. Ops/sec without fix - 305792.03 Ops/sec with fix - 521942.24 This patch (of 2): Instead of using 'cpu_to_node()', we use 'numa_node_id()', which is quicker. smp_processor_id is guaranteed to be stable in the 'mpol_misplaced()' function because it is called with ptl held. lockdep_assert_held was added to ensure that. No functional change in this patch. [donettom@linux.ibm.com: add "* @vmf: structure describing the fault" comment] Link: https://lkml.kernel.org/r/d8b993ea9dccfac0bc3ed61d3a81f4ac5f376e46.1711002865.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/cover.1711373653.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/6059f034f436734b472d066db69676fb3a459864.1711373653.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/cover.1709909210.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/744646531af02cc687cde8ae788fb1779e99d02c.1709909210.git.donettom@linux.ibm.com Signed-off-by: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org> Signed-off-by: Donet Tom <donettom@linux.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm/treewide: replace pXd_huge() with pXd_leaf()Peter Xu
Now after we're sure all pXd_huge() definitions are the same as pXd_leaf(), reuse it. Luckily, pXd_huge() isn't widely used. Link: https://lkml.kernel.org/r/20240318200404.448346-12-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Andersson <andersson@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Fabio Estevam <festevam@denx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Mark Salter <msalter@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-19Merge x86 bugfixes from Linux 6.9-rc3Paolo Bonzini
Pull fix for SEV-SNP late disable bugs. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-04-12mm: replace set_pte_at_notify() with just set_pte_at()Paolo Bonzini
With the demise of the .change_pte() MMU notifier callback, there is no notification happening in set_pte_at_notify(). It is a synonym of set_pte_at() and can be replaced with it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-ID: <20240405115815.3226315-5-pbonzini@redhat.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-04-05x86/mm/pat: fix VM_PAT handling in COW mappingsDavid Hildenbrand
PAT handling won't do the right thing in COW mappings: the first PTE (or, in fact, all PTEs) can be replaced during write faults to point at anon folios. Reliably recovering the correct PFN and cachemode using follow_phys() from PTEs will not work in COW mappings. Using follow_phys(), we might just get the address+protection of the anon folio (which is very wrong), or fail on swap/nonswap entries, failing follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and track_pfn_copy(), not properly calling free_pfn_range(). In free_pfn_range(), we either wouldn't call memtype_free() or would call it with the wrong range, possibly leaking memory. To fix that, let's update follow_phys() to refuse returning anon folios, and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings if we run into that. We will now properly handle untrack_pfn() with COW mappings, where we don't need the cachemode. We'll have to fail fork()->track_pfn_copy() if the first page was replaced by an anon folio, though: we'd have to store the cachemode in the VMA to make this work, likely growing the VMA size. For now, lets keep it simple and let track_pfn_copy() just fail in that case: it would have failed in the past with swap/nonswap entries already, and it would have done the wrong thing with anon folios. Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn(): <--- C reproducer ---> #include <stdio.h> #include <sys/mman.h> #include <unistd.h> #include <liburing.h> int main(void) { struct io_uring_params p = {}; int ring_fd; size_t size; char *map; ring_fd = io_uring_setup(1, &p); if (ring_fd < 0) { perror("io_uring_setup"); return 1; } size = p.sq_off.array + p.sq_entries * sizeof(unsigned); /* Map the submission queue ring MAP_PRIVATE */ map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, ring_fd, IORING_OFF_SQ_RING); if (map == MAP_FAILED) { perror("mmap"); return 1; } /* We have at least one page. Let's COW it. */ *map = 0; pause(); return 0; } <--- C reproducer ---> On a system with 16 GiB RAM and swap configured: # ./iouring & # memhog 16G # killall iouring [ 301.552930] ------------[ cut here ]------------ [ 301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100 [ 301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g [ 301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1 [ 301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4 [ 301.559569] RIP: 0010:untrack_pfn+0xf4/0x100 [ 301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000 [ 301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282 [ 301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047 [ 301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200 [ 301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000 [ 301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000 [ 301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000 [ 301.564186] FS: 0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000 [ 301.564773] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0 [ 301.565725] PKRU: 55555554 [ 301.565944] Call Trace: [ 301.566148] <TASK> [ 301.566325] ? untrack_pfn+0xf4/0x100 [ 301.566618] ? __warn+0x81/0x130 [ 301.566876] ? untrack_pfn+0xf4/0x100 [ 301.567163] ? report_bug+0x171/0x1a0 [ 301.567466] ? handle_bug+0x3c/0x80 [ 301.567743] ? exc_invalid_op+0x17/0x70 [ 301.568038] ? asm_exc_invalid_op+0x1a/0x20 [ 301.568363] ? untrack_pfn+0xf4/0x100 [ 301.568660] ? untrack_pfn+0x65/0x100 [ 301.568947] unmap_single_vma+0xa6/0xe0 [ 301.569247] unmap_vmas+0xb5/0x190 [ 301.569532] exit_mmap+0xec/0x340 [ 301.569801] __mmput+0x3e/0x130 [ 301.570051] do_exit+0x305/0xaf0 ... Link: https://lkml.kernel.org/r/20240403212131.929421-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Wupeng Ma <mawupeng1@huawei.com> Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@huawei.com Fixes: b1a86e15dc03 ("x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines") Fixes: 5899329b1910 ("x86: PAT: implement track/untrack of pfnmap regions for x86 - v3") Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-26mm/memory: fix missing pte marker for !page on pte zapsPeter Xu
Commit 0cf18e839f64 of large folio zap work broke uffd-wp. Now mm's uffd unit test "wp-unpopulated" will trigger this WARN_ON_ONCE(). The WARN_ON_ONCE() asserts that an VMA cannot be registered with userfaultfd-wp if it contains a !normal page, but it's actually possible. One example is an anonymous vma, register with uffd-wp, read anything will install a zero page. Then when zap on it, this should trigger. What's more, removing that WARN_ON_ONCE may not be enough either, because we should also not rely on "whether it's a normal page" to decide whether pte marker is needed. For example, one can register wr-protect over some DAX regions to track writes when UFFD_FEATURE_WP_ASYNC enabled, in which case it can have page==NULL for a devmap but we may want to keep the marker around. Link: https://lkml.kernel.org/r/20240313213107.235067-1-peterx@redhat.com Fixes: 0cf18e839f64 ("mm/memory: handle !page case in zap_present_pte() separately") Signed-off-by: Peter Xu <peterx@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-13mm: prohibit the last subpage from reusing the entire large folioBarry Song
In a Copy-on-Write (CoW) scenario, the last subpage will reuse the entire large folio, resulting in the waste of (nr_pages - 1) pages. This wasted memory remains allocated until it is either unmapped or memory reclamation occurs. The following small program can serve as evidence of this behavior main() { #define SIZE 1024 * 1024 * 1024UL void *p = malloc(SIZE); memset(p, 0x11, SIZE); if (fork() == 0) _exit(0); memset(p, 0x12, SIZE); printf("done\n"); while(1); } For example, using a 1024KiB mTHP by: echo always > /sys/kernel/mm/transparent_hugepage/hugepages-1024kB/enabled (1) w/o the patch, it takes 2GiB, Before running the test program, / # free -m total used free shared buff/cache available Mem: 5754 84 5692 0 17 5669 Swap: 0 0 0 / # /a.out & / # done After running the test program, / # free -m total used free shared buff/cache available Mem: 5754 2149 3627 0 19 3605 Swap: 0 0 0 (2) w/ the patch, it takes 1GiB only, Before running the test program, / # free -m total used free shared buff/cache available Mem: 5754 89 5687 0 17 5664 Swap: 0 0 0 / # /a.out & / # done After running the test program, / # free -m total used free shared buff/cache available Mem: 5754 1122 4655 0 17 4632 Swap: 0 0 0 This patch migrates the last subpage to a small folio and immediately returns the large folio to the system. It benefits both memory availability and anti-fragmentation. Link: https://lkml.kernel.org/r/20240308092721.144735-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Lance Yang <ioworker0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-06mm: memory: fix shift-out-of-bounds in fault_around_bytes_setKefeng Wang
The rounddown_pow_of_two(0) is undefined, so val = 0 is not allowed in the fault_around_bytes_set(), and leads to shift-out-of-bounds, UBSAN: shift-out-of-bounds in include/linux/log2.h:67:13 shift exponent 4294967295 is too large for 64-bit type 'long unsigned int' CPU: 7 PID: 107 Comm: sh Not tainted 6.8.0-rc6-next-20240301 #294 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 Call trace: dump_backtrace+0x94/0xec show_stack+0x18/0x24 dump_stack_lvl+0x78/0x90 dump_stack+0x18/0x24 ubsan_epilogue+0x10/0x44 __ubsan_handle_shift_out_of_bounds+0x98/0x134 fault_around_bytes_set+0xa4/0xb0 simple_attr_write_xsigned.isra.0+0xe4/0x1ac simple_attr_write+0x18/0x24 debugfs_attr_write+0x4c/0x98 vfs_write+0xd0/0x4b0 ksys_write+0x6c/0xfc __arm64_sys_write+0x1c/0x28 invoke_syscall+0x44/0x104 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x34/0xdc el0t_64_sync_handler+0xc0/0xc4 el0t_64_sync+0x190/0x194 ---[ end trace ]--- Fix it by setting the minimum val to PAGE_SIZE. Link: https://lkml.kernel.org/r/20240302064312.2358924-1-wangkefeng.wang@huawei.com Fixes: 53d36a56d8c4 ("mm: prefer fault_around_pages to fault_around_bytes") Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reported-by: Yue Sun <samsun1006219@gmail.com> Closes: https://lore.kernel.org/all/CAEkJfYPim6DQqW1GqCiHLdh2-eweqk1fGyXqs3JM+8e1qGge8w@mail.gmail.com/ Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-06mm: make folio_pte_batch available outside of mm/memory.cBarry Song
madvise, mprotect and some others might need folio_pte_batch to check if a range of PTEs are completely mapped to a large folio with contiguous physical addresses. Let's make it available in mm/internal.h. While at it, add proper kernel doc and sanity-check more input parameters using two additional VM_WARN_ON_FOLIO(). [21cnbao@gmail.com: build fix] Link: https://lkml.kernel.org/r/CAGsJ_4wWzG-37D82vqP_zt+Fcbz+URVe5oXLBc4M5wbN8A_gpQ@mail.gmail.com [david@redhat.com: improve the doc for the exported func] Link: https://lkml.kernel.org/r/20240227104201.337988-1-21cnbao@gmail.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Barry Song <v-songbaohua@oppo.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04mm/memory.c: do_numa_page(): remove a redundant page table readJohn Hubbard
do_numa_page() is reading from the same page table entry, twice, while holding the page table lock: once while checking that the pte hasn't changed, and again in order to modify the pte. Instead, just read the pte once, and save it in the same old_pte variable that already exists. This has no effect on behavior, other than to provide a tiny potential improvement to performance, by avoiding the redundant memory read (which the compiler cannot elide, due to READ_ONCE()). Also improve the associated comments nearby. Link: https://lkml.kernel.org/r/20240228034151.459370-1-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04mm: convert free_swap_cache() to take a folioMatthew Wilcox (Oracle)
All but one caller already has a folio, so convert free_page_and_swap_cache() to have a folio and remove the call to page_folio(). Link: https://lkml.kernel.org/r/20240227174254.710559-19-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04mm/memory: change vmf_anon_prepare() to be non-staticVishal Moola (Oracle)
Patch series "Handle hugetlb faults under the VMA lock", v2. It is generally safe to handle hugetlb faults under the VMA lock. The only time this is unsafe is when no anon_vma has been allocated to this vma yet, so we can use vmf_anon_prepare() instead of anon_vma_prepare() to bailout if necessary. This should only happen for the first hugetlb page in the vma. Additionally, this patchset begins to use struct vm_fault within hugetlb_fault(). This works towards cleaning up hugetlb code, and should significantly reduce the number of arguments passed to functions. The last patch in this series may cause ltp hugemmap10 to "fail". This is because vmf_anon_prepare() may bailout with no anon_vma under the VMA lock after allocating a folio for the hugepage. In free_huge_folio(), this folio is completely freed on bailout iff there is a surplus of hugetlb pages. This will remove a folio off the freelist and decrement the number of hugepages while ltp expects these counters to remain unchanged on failure. The rest of the ltp testcases pass. This patch (of 2): In order to handle hugetlb faults under the VMA lock, hugetlb can use vmf_anon_prepare() to ensure we can safely prepare an anon_vma. Change it to be a non-static function so it can be used within hugetlb as well. Link: https://lkml.kernel.org/r/20240221234732.187629-6-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20240221234732.187629-2-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm: add pte_batch_hint() to reduce scanning in folio_pte_batch()Ryan Roberts
Some architectures (e.g. arm64) can tell from looking at a pte, if some follow-on ptes also map contiguous physical memory with the same pgprot. (for arm64, these are contpte mappings). Take advantage of this knowledge to optimize folio_pte_batch() so that it can skip these ptes when scanning to create a batch. By default, if an arch does not opt-in, folio_pte_batch() returns a compile-time 1, so the changes are optimized out and the behaviour is as before. arm64 will opt-in to providing this hint in the next patch, which will greatly reduce the cost of ptep_get() when scanning a range of contptes. Link: https://lkml.kernel.org/r/20240215103205.2607016-16-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: John Hubbard <jhubbard@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Barry Song <21cnbao@gmail.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morse <james.morse@arm.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: optimize unmap/zap with PTE-mapped THPDavid Hildenbrand
Similar to how we optimized fork(), let's implement PTE batching when consecutive (present) PTEs map consecutive pages of the same large folio. Most infrastructure we need for batching (mmu gather, rmap) is already there. We only have to add get_and_clear_full_ptes() and clear_full_ptes(). Similarly, extend zap_install_uffd_wp_if_needed() to process a PTE range. We won't bother sanity-checking the mapcount of all subpages, but only check the mapcount of the first subpage we process. If there is a real problem hiding somewhere, we can trigger it simply by using small folios, or when we zap single pages of a large folio. Ideally, we had that check in rmap code (including for delayed rmap), but then we cannot print the PTE. Let's keep it simple for now. If we ever have a cheap folio_mapcount(), we might just want to check for underflows there. To keep small folios as fast as possible force inlining of a specialized variant using __always_inline with nr=1. Link: https://lkml.kernel.org/r/20240214204435.167852-11-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: factor out zapping folio pte into zap_present_folio_pte()David Hildenbrand
Let's prepare for further changes by factoring it out into a separate function. Link: https://lkml.kernel.org/r/20240214204435.167852-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: further separate anon and pagecache folio handling in ↵David Hildenbrand
zap_present_pte() We don't need up-to-date accessed-dirty information for anon folios and can simply work with the ptent we already have. Also, we know the RSS counter we want to update. We can safely move arch_check_zapped_pte() + tlb_remove_tlb_entry() + zap_install_uffd_wp_if_needed() after updating the folio and RSS. While at it, only call zap_install_uffd_wp_if_needed() if there is even any chance that pte_install_uffd_wp_if_needed() would do *something*. That is, just don't bother if uffd-wp does not apply. Link: https://lkml.kernel.org/r/20240214204435.167852-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: handle !page case in zap_present_pte() separatelyDavid Hildenbrand
We don't need uptodate accessed/dirty bits, so in theory we could replace ptep_get_and_clear_full() by an optimized ptep_clear_full() function. Let's rely on the provided pte. Further, there is no scenario where we would have to insert uffd-wp markers when zapping something that is not a normal page (i.e., zeropage). Add a sanity check to make sure this remains true. should_zap_folio() no longer has to handle NULL pointers. This change replaces 2/3 "!page/!folio" checks by a single "!page" one. Note that arch_check_zapped_pte() on x86-64 checks the HW-dirty bit to detect shadow stack entries. But for shadow stack entries, the HW dirty bit (in combination with non-writable PTEs) is set by software. So for the arch_check_zapped_pte() check, we don't have to sync against HW setting the HW dirty bit concurrently, it is always set. Link: https://lkml.kernel.org/r/20240214204435.167852-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: factor out zapping of present pte into zap_present_pte()David Hildenbrand
Patch series "mm/memory: optimize unmap/zap with PTE-mapped THP", v3. This series is based on [1]. Similar to what we did with fork(), let's implement PTE batching during unmap/zap when processing PTE-mapped THPs. We collect consecutive PTEs that map consecutive pages of the same large folio, making sure that the other PTE bits are compatible, and (a) adjust the refcount only once per batch, (b) call rmap handling functions only once per batch, (c) perform batch PTE setting/updates and (d) perform TLB entry removal once per batch. Ryan was previously working on this in the context of cont-pte for arm64, int latest iteration [2] with a focus on arm6 with cont-pte only. This series implements the optimization for all architectures, independent of such PTE bits, teaches MMU gather/TLB code to be fully aware of such large-folio-pages batches as well, and amkes use of our new rmap batching function when removing the rmap. To achieve that, we have to enlighten MMU gather / page freeing code (i.e., everything that consumes encoded_page) to process unmapping of consecutive pages that all belong to the same large folio. I'm being very careful to not degrade order-0 performance, and it looks like I managed to achieve that. While this series should -- similar to [1] -- be beneficial for adding cont-pte support on arm64[2], it's one of the requirements for maintaining a total mapcount[3] for large folios with minimal added overhead and further changes[4] that build up on top of the total mapcount. Independent of all that, this series results in a speedup during munmap() and similar unmapping (process teardown, MADV_DONTNEED on larger ranges) with PTE-mapped THP, which is the default with THPs that are smaller than a PMD (for example, 16KiB to 1024KiB mTHPs for anonymous memory[5]). On an Intel Xeon Silver 4210R CPU, munmap'ing a 1GiB VMA backed by PTE-mapped folios of the same size (stddev < 1%) results in the following runtimes for munmap() in seconds (shorter is better): Folio Size | mm-unstable | New | Change --------------------------------------------- 4KiB | 0.058110 | 0.057715 | - 1% 16KiB | 0.044198 | 0.035469 | -20% 32KiB | 0.034216 | 0.023522 | -31% 64KiB | 0.029207 | 0.018434 | -37% 128KiB | 0.026579 | 0.014026 | -47% 256KiB | 0.025130 | 0.011756 | -53% 512KiB | 0.024292 | 0.010703 | -56% 1024KiB | 0.023812 | 0.010294 | -57% 2048KiB | 0.023785 | 0.009910 | -58% [1] https://lkml.kernel.org/r/20240129124649.189745-1-david@redhat.com [2] https://lkml.kernel.org/r/20231218105100.172635-1-ryan.roberts@arm.com [3] https://lkml.kernel.org/r/20230809083256.699513-1-david@redhat.com [4] https://lkml.kernel.org/r/20231124132626.235350-1-david@redhat.com [5] https://lkml.kernel.org/r/20231207161211.2374093-1-ryan.roberts@arm.com This patch (of 10): Let's prepare for further changes by factoring out processing of present PTEs. Link: https://lkml.kernel.org/r/20240214204435.167852-1-david@redhat.com Link: https://lkml.kernel.org/r/20240214204435.167852-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: ignore writable bit in folio_pte_batch()David Hildenbrand
... and conditionally return to the caller if any PTE except the first one is writable. fork() has to make sure to properly write-protect in case any PTE is writable. Other users (e.g., page unmaping) are expected to not care. Link: https://lkml.kernel.org/r/20240129124649.189745-16-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: ignore dirty/accessed/soft-dirty bits in folio_pte_batch()David Hildenbrand
Let's always ignore the accessed/young bit: we'll always mark the PTE as old in our child process during fork, and upcoming users will similarly not care. Ignore the dirty bit only if we don't want to duplicate the dirty bit into the child process during fork. Maybe, we could just set all PTEs in the child dirty if any PTE is dirty. For now, let's keep the behavior unchanged, this can be optimized later if required. Ignore the soft-dirty bit only if the bit doesn't have any meaning in the src vma, and similarly won't have any in the copied dst vma. For now, we won't bother with the uffd-wp bit. Link: https://lkml.kernel.org/r/20240129124649.189745-15-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: optimize fork() with PTE-mapped THPDavid Hildenbrand
Let's implement PTE batching when consecutive (present) PTEs map consecutive pages of the same large folio, and all other PTE bits besides the PFNs are equal. We will optimize folio_pte_batch() separately, to ignore selected PTE bits. This patch is based on work by Ryan Roberts. Use __always_inline for __copy_present_ptes() and keep the handling for single PTEs completely separate from the multi-PTE case: we really want the compiler to optimize for the single-PTE case with small folios, to not degrade performance. Note that PTE batching will never exceed a single page table and will always stay within VMA boundaries. Further, processing PTE-mapped THP that maybe pinned and have PageAnonExclusive set on at least one subpage should work as expected, but there is room for improvement: We will repeatedly (1) detect a PTE batch (2) detect that we have to copy a page (3) fall back and allocate a single page to copy a single page. For now we won't care as pinned pages are a corner case, and we should rather look into maintaining only a single PageAnonExclusive bit for large folios. Link: https://lkml.kernel.org/r/20240129124649.189745-14-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: pass PTE to copy_present_pte()David Hildenbrand
We already read it, let's just forward it. This patch is based on work by Ryan Roberts. [david@redhat.com: fix the hmm "exclusive_cow" selftest] Link: https://lkml.kernel.org/r/13f296b8-e882-47fd-b939-c2141dc28717@redhat.com Link: https://lkml.kernel.org/r/20240129124649.189745-13-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/memory: factor out copying the actual PTE in copy_present_pte()David Hildenbrand
Let's prepare for further changes. Link: https://lkml.kernel.org/r/20240129124649.189745-12-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King (Oracle) <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm: memory: move mem_cgroup_charge() into alloc_anon_folio()Kefeng Wang
The GFP flags from vma_thp_gfp_mask() according to user configuration only used for large folio allocation but not for memory cgroup charge, and GFP_KERNEL is used for both order-0 and large order folio when memory cgroup charge at present. However, mem_cgroup_charge() uses the GFP flags in a fairly sophisticated way. In addition to checking gfpflags_allow_blocking(), it pays attention to __GFP_NORETRY and __GFP_RETRY_MAYFAIL to ensure that processes within this memcg do not exceed their quotas. So we'd better to move mem_cgroup_charge() into alloc_anon_folio(), 1) it will make us to allocate as much as possible large order folio, because we could try the next order if mem_cgroup_charge() fails, although the memcg's memory usage is close to its limits. 2) using same GFP flags for allocation and charge is to be consistent with PMD THP firstly, in addition, according to GFP flag returned from vma_thp_gfp_mask(), GFP_TRANSHUGE_LIGHT could make us skip direct reclaim, _GFP_NORETRY will make us skip mem_cgroup_oom() and won't trigger memory cgroup oom from large order(order <= COSTLY_ORDER) folio charging. Link: https://lkml.kernel.org/r/20240122011612.501029-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20240117103954.2756050-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-21mm: convert mm_counter_file() to take a folioKefeng Wang
Now all callers of mm_counter_file() have a folio, convert mm_counter_file() to take a folio. Saves a call to compound_head() hidden inside PageSwapBacked(). Link: https://lkml.kernel.org/r/20240111152429.3374566-11-willy@infradead.org Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>