- 16 Jan, 2022 1 commit
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git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblockLinus Torvalds authored
Pull memblock cleanup from Mike Rapoport: "Remove #ifdef __KERNEL__ from memblock.h memblock.h is not a uAPI header, so __KERNEL__ guard can be deleted" * tag 'memblock-v5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock: Remove #ifdef __KERNEL__ from memblock.h
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- 15 Jan, 2022 39 commits
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Linus Torvalds authored
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 ...
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SeongJae Park authored
DAMON's virtual address spaces monitoring primitive uses 'struct pid *' of the target process as its monitoring target id. The kernel address is exposed as-is to the user space via the DAMON tracepoint, 'damon_aggregated'. Though primarily only privileged users are allowed to access that, it would be better to avoid unnecessarily exposing kernel pointers so. Because the trace result is only required to be able to distinguish each target, we aren't need to use the pointer as-is. This makes the tracepoint to use the index of the target in the context's targets list as its id in the tracepoint, to hide the kernel space address. Link: https://lkml.kernel.org/r/20211229131016.23641-5-sj@kernel.orgSigned-off-by:
SeongJae Park <sj@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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SeongJae Park authored
The failure log message for 'damon_va_three_regions()' prints the target id, which is a 'struct pid' pointer in the case. To avoid exposing the kernel pointer via the log, this makes the log to use the index of the target in the context's targets list instead. Link: https://lkml.kernel.org/r/20211229131016.23641-4-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Failure of 'damon_va_three_regions()' is logged using 'pr_err()'. But, the function can fail in legal situations. To avoid making users be surprised and to keep the kernel clean, this makes the log to be printed using 'pr_debug()'. Link: https://lkml.kernel.org/r/20211229131016.23641-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch series "mm/damon: Hide unnecessary information disclosures". DAMON is exposing some unnecessary information including kernel pointer in kernel log and tracepoint. This patchset hides such information. The first patch is only for a trivial cleanup, though. This patch (of 4): This commit removes a unnecessarily used variable in dbgfs_target_ids_write(). Link: https://lkml.kernel.org/r/20211229131016.23641-1-sj@kernel.org Link: https://lkml.kernel.org/r/20211229131016.23641-2-sj@kernel.org Fixes: 4bc05954 ("mm/damon: implement a debugfs-based user space interface") Signed-off-by:
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Guoqing Jiang authored
Usually, inline function is declared static since it should sit between storage and type. And implement it in a header file if used by multiple files. And this change also fixes compile issue when backport damon to 5.10. mm/damon/vaddr.c: In function `damon_va_evenly_split_region': ./include/linux/damon.h:425:13: error: inlining failed in call to `always_inline' `damon_insert_region': function body not available 425 | inline void damon_insert_region(struct damon_region *r, | ^~~~~~~~~~~~~~~~~~~ mm/damon/vaddr.c:86:3: note: called from here 86 | damon_insert_region(n, r, next, t); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Link: https://lkml.kernel.org/r/20211223085703.6142-1-guoqing.jiang@linux.devSigned-off-by:Guoqing Jiang <guoqing.jiang@linux.dev> Reviewed-by:
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Baolin Wang authored
The process's VMAs can be mapped by hugetlb page, but now the DAMON did not implement the access checking for hugetlb pte, so we can not get the actual access count like below if a process VMAs were mapped by hugetlb. damon_aggregated: target_id=18446614368406014464 nr_regions=12 4194304-5476352: 0 545 damon_aggregated: target_id=18446614368406014464 nr_regions=12 140662370467840-140662372970496: 0 545 damon_aggregated: target_id=18446614368406014464 nr_regions=12 140662372970496-140662375460864: 0 545 damon_aggregated: target_id=18446614368406014464 nr_regions=12 140662375460864-140662377951232: 0 545 damon_aggregated: target_id=18446614368406014464 nr_regions=12 140662377951232-140662380449792: 0 545 damon_aggregated: target_id=18446614368406014464 nr_regions=12 140662380449792-140662382944256: 0 545 ...... Thus this patch adds hugetlb access checking support, with this patch we can see below VMA mapped by hugetlb access count. damon_aggregated: target_id=18446613056935405824 nr_regions=12 140296486649856-140296489914368: 1 3 damon_aggregated: target_id=18446613056935405824 nr_regions=12 140296489914368-140296492978176: 1 3 damon_aggregated: target_id=18446613056935405824 nr_regions=12 140296492978176-140296495439872: 1 3 damon_aggregated: target_id=18446613056935405824 nr_regions=12 140296495439872-140296498311168: 1 3 damon_aggregated: target_id=18446613056935405824 nr_regions=12 140296498311168-140296501198848: 1 3 damon_aggregated: target_id=18446613056935405824 nr_regions=12 140296501198848-140296504320000: 1 3 damon_aggregated: target_id=18446613056935405824 nr_regions=12 140296504320000-140296507568128: 1 2 ...... [baolin.wang@linux.alibaba.com: fix unused var warning] Link: https://lkml.kernel.org/r/1aaf9c11-0d8e-b92d-5c92-46e50a6e8d4e@linux.alibaba.com [baolin.wang@linux.alibaba.com: v3] Link: https://lkml.kernel.org/r/486927ecaaaecf2e3a7fbe0378ec6e1c58b50747.1640852276.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/6afcbd1fda5f9c7c24f320d26a98188c727ceec3.1639623751.git.baolin.wang@linux.alibaba.comSigned-off-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by:
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SeongJae Park authored
This updates DAMON debugfs interface for statistics of schemes successfully applied regions and time/space quota limit exceeds counts. Link: https://lkml.kernel.org/r/20211210150016.35349-7-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Currently, DAMON debugfs interface is not supporting DAMON-based Operation Schemes (DAMOS) stats for schemes successfully applied regions and time/space quota limit exceeds. This adds the support. Link: https://lkml.kernel.org/r/20211210150016.35349-6-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This adds descriptions for the DAMON_RECLAIM statistics parameters. Link: https://lkml.kernel.org/r/20211210150016.35349-5-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
This implements new DAMON_RECLAIM parameters for statistics reporting. Those can be used for understanding how DAMON_RECLAIM is working, and for tuning the other parameters. Link: https://lkml.kernel.org/r/20211210150016.35349-4-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
If the time/space quotas of a given DAMON-based operation scheme is too small, the scheme could show unexpectedly slow progress. However, there is no good way to notice the case in runtime. This commit extends the DAMOS stat to provide how many times the quota limits exceeded so that the users can easily notice the case and tune the scheme. Link: https://lkml.kernel.org/r/20211210150016.35349-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch series "mm/damon/schemes: Extend stats for better online analysis and tuning". To help online access pattern analysis and tuning of DAMON-based Operation Schemes (DAMOS), DAMOS provides simple statistics for each scheme. Introduction of DAMOS time/space quota further made the tuning easier by making the risk management easier. However, that also made understanding of the working schemes a little bit more difficult. For an example, progress of a given scheme can now be throttled by not only the aggressiveness of the target access pattern, but also the time/space quotas. So, when a scheme is showing unexpectedly slow progress, it's difficult to know by what the progress of the scheme is throttled, with currently provided statistics. This patchset extends the statistics to contain some metrics that can be helpful for such online schemes analysis and tuning (patches 1-2), exports those to users (patches 3 and 5), and add documents (patches 4 and 6). This patch (of 6): DAMON-based operation schemes (DAMOS) stats provide only the number and the amount of regions that the action of the scheme has tried to be applied. Because the action could be failed for some reasons, the currently provided information is sometimes not useful or convenient enough for schemes profiling and tuning. To improve this situation, this commit extends the DAMOS stats to provide the number and the amount of regions that the action has successfully applied. Link: https://lkml.kernel.org/r/20211210150016.35349-1-sj@kernel.org Link: https://lkml.kernel.org/r/20211210150016.35349-2-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Due to a mistake in patches reordering, a comment for a future feature called 'arbitrary monitoring target support'[1], which is still under development, has added. Because it only introduces confusion and we don't have a plan to post the patches soon, this commit removes the mistakenly added part. [1] https://lore.kernel.org/linux-mm/20201215115448.25633-3-sjpark@amazon.com/ Link: https://lkml.kernel.org/r/20211209131806.19317-7-sj@kernel.org Fixes: 1f366e42 ("mm/damon/core: implement DAMON-based Operation Schemes (DAMOS)") Signed-off-by:
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SeongJae Park authored
The DAMON debugfs usage document is missing descriptions for 'kdamond_pid', 'mk_contexts', and 'rm_contexts' debugfs files. This commit adds those. Link: https://lkml.kernel.org/r/20211209131806.19317-6-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
To get detailed monitoring results from the user space, users need to use the damon_aggregated tracepoint. This commit adds a brief mention of it at the beginning of the usage document. Link: https://lkml.kernel.org/r/20211209131806.19317-5-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
DAMON usage document mentions DAMON user space tool and programming interface twice. This commit integrates those and remove unnecessary part. Link: https://lkml.kernel.org/r/20211209131806.19317-4-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
DAMOS features including time/space quota limits and watermarks are not described in the DAMON debugfs interface document. This commit updates the document for the features. Link: https://lkml.kernel.org/r/20211209131806.19317-3-sj@kernel.orgSigned-off-by:
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SeongJae Park authored
Patch series "mm/damon: Misc cleanups". This patchset contains miscellaneous cleanups for DAMON's macro functions and documentation. This patch (of 6): This commit converts macro functions in DAMON to static inline functions, for better type checking, code documentation, etc[1]. [1] https://lore.kernel.org/linux-mm/20211202151213.6ec830863342220da4141bc5@linux-foundation.org/ Link: https://lkml.kernel.org/r/20211209131806.19317-1-sj@kernel.org Link: https://lkml.kernel.org/r/20211209131806.19317-2-sj@kernel.orgSigned-off-by:
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Xin Hao authored
damon_rand() cannot be implemented as a macro. Example: damon_rand(a++, b); The value of 'a' will be incremented twice, This is obviously unreasonable, So there fix it. Link: https://lkml.kernel.org/r/110ffcd4e420c86c42b41ce2bc9f0fe6a4f32cd3.1638795127.git.xhao@linux.alibaba.com Fixes: b9a6ac4e ("mm/damon: adaptively adjust regions") Signed-off-by:
Xin Hao <xhao@linux.alibaba.com> Reported-by:
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Xin Hao authored
damon_rand() is called in three files:damon/core.c, damon/ paddr.c, damon/vaddr.c, i think there is no need to redefine this twice, So move it to damon.h will be a good choice. Link: https://lkml.kernel.org/r/20211202075859.51341-1-xhao@linux.alibaba.comSigned-off-by:
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Xin Hao authored
In dbgfs "schemes" interface, i do some test like this: # cd /sys/kernel/debug/damon # echo "2 1 2 1 10 1 3 10 1 1 1 1 1 1 1 1 2 3" > schemes # cat schemes # 2 1 2 1 10 1 3 10 1 1 1 1 1 1 1 1 2 3 0 0 There have some unreasonable places, i set the valules of these variables "<min_sz, max_sz> <min_nr_a, max_nr_a>, <min_age, max_age>, <wmarks.high, wmarks.mid, wmarks.low>" as "<2, 1>, <2, 1>, <10, 1>, <1, 2, 3>. So there add a validity judgment for these thresholds value. Link: https://lkml.kernel.org/r/d78360e52158d786fcbf20bc62c96785742e76d3.1637239568.git.xhao@linux.alibaba.comSigned-off-by: -
Yihao Han authored
Remove 'swap_ranges()' and replace it with the macro 'swap()' defined in 'include/linux/minmax.h' to simplify code and improve efficiency Link: https://lkml.kernel.org/r/20211111115355.2808-1-hanyihao@vivo.comSigned-off-by:
Yihao Han <hanyihao@vivo.com> Reviewed-by:
Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Xin Hao authored
In damon.h some func definitions about VA & PA can only be used in its own file, so there no need to define in the header file, and the header file will look cleaner. If other files later need these functions, the prototypes can be added to damon.h at that time. [sj@kernel.org: remove unnecessary function prototype position changes] Link: https://lkml.kernel.org/r/20211118114827.20052-1-sj@kernel.org Link: https://lkml.kernel.org/r/45fd5b3ef6cce8e28dbc1c92f9dc845ccfc949d7.1636989871.git.xhao@linux.alibaba.comSigned-off-by:
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Xin Hao authored
In kernel, we can use abs(a - b) to get the absolute value, So there is no need to redefine a new one. Link: https://lkml.kernel.org/r/b24e7b82d9efa90daf150d62dea171e19390ad0b.1636989871.git.xhao@linux.alibaba.comSigned-off-by:
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Xin Hao authored
In Damon, we can get age information by analyzing the nr_access change, But short time sampling is not effective, we have to obtain enough data for analysis through long time trace, this also means that we need to consume more cpu resources and storage space. Now the region add a new 'age' variable, we only need to get the change of age value through a little time trace, for example, age has been increasing to 141, but nr_access shows a value of 0 at the same time, Through this，we can conclude that the region has a very low nr_access value for a long time. Link: https://lkml.kernel.org/r/b9def1262af95e0dc1d0caea447886434db01161.1636989871.git.xhao@linux.alibaba.comSigned-off-by:
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Xin Hao authored
Patch series "mm/damon: Do some small changes", v4. This patch (of 4): In damon/paddr.c file, two functions names start with underscore, static void __damon_pa_prepare_access_check(struct damon_ctx *ctx, struct damon_region *r) static void __damon_pa_prepare_access_check(struct damon_ctx *ctx, struct damon_region *r) In damon/vaddr.c file, there are also two functions with the same function, static void damon_va_prepare_access_check(struct damon_ctx *ctx, struct mm_struct *mm, struct damon_region *r) static void damon_va_check_access(struct damon_ctx *ctx, struct mm_struct *mm, struct damon_region *r) It makes sense to keep consistent, and it is not easy to be confused with the function that call them. Link: https://lkml.kernel.org/r/cover.1636989871.git.xhao@linux.alibaba.com Link: https://lkml.kernel.org/r/529054aed932a42b9c09fc9977ad4574b9e7b0bd.1636989871.git.xhao@linux.alibaba.comSigned-off-by:
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Alistair Popple authored
hmm_range_fault() can be used instead of get_user_pages() for devices which allow faulting however unlike get_user_pages() it will return an error when used on a VM_MIXEDMAP range. To make hmm_range_fault() more closely match get_user_pages() remove this restriction. This requires dealing with the !ARCH_HAS_PTE_SPECIAL case in hmm_vma_handle_pte(). Rather than replicating the logic of vm_normal_page() call it directly and do a check for the zero pfn similar to what get_user_pages() currently does. Also add a test to hmm selftest to verify functionality. Link: https://lkml.kernel.org/r/20211104012001.2555676-1-apopple@nvidia.com Fixes: da4c3c73 ("mm/hmm/mirror: helper to snapshot CPU page table") Signed-off-by:
Alistair Popple <apopple@nvidia.com> Reviewed-by:
Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Signed-off-by:
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Ting Liu authored
"page_idle_ops" as a global var, but its scope of use within this document. So it should be static. "page_ext_ops" is a var used in the kernel initial phase. And other functions are aslo used in the kernel initial phase. So they should be __init or __initdata to reclaim memory. Link: https://lkml.kernel.org/r/20211217095023.67293-1-liuting.0x7c00@bytedance.comSigned-off-by:
Ting Liu <liuting.0x7c00@bytedance.com> Signed-off-by:
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Quanfa Fu authored
Link: https://lkml.kernel.org/r/20211101040208.460810-1-fuqf0919@gmail.comSigned-off-by:
Quanfa Fu <fuqf0919@gmail.com> Signed-off-by:
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Luis Chamberlain authored
Embrace ATTRIBUTE_GROUPS to avoid boiler plate code. This should not introduce any functional changes. Link: https://lkml.kernel.org/r/20211028203600.2157356-1-mcgrof@kernel.orgSigned-off-by:
Luis Chamberlain <mcgrof@kernel.org> Reviewed-by:
Bart Van Assche <bvanassche@acm.org> Reviewed-by:
Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by:
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Zhaoyu Liu authored
The list of pools_head is no longer needed because the caller has been deleted in commit 479305fd ("zpool: remove zpool_evict()"). Link: https://lkml.kernel.org/r/20211215163727.GA17196@pcSigned-off-by:
Zhaoyu Liu <zackary.liu.pro@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by:
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Huang Ying authored
In theory, the following race is possible for batched TLB flushing. CPU0 CPU1 ---- ---- shrink_page_list() unmap zap_pte_range() flush_tlb_batched_pending() flush_tlb_mm() try_to_unmap() set_tlb_ubc_flush_pending() mm->tlb_flush_batched = true mm->tlb_flush_batched = false After the TLB is flushed on CPU1 via flush_tlb_mm() and before mm->tlb_flush_batched is set to false, some PTE is unmapped on CPU0 and the TLB flushing is pended. Then the pended TLB flushing will be lost. Although both set_tlb_ubc_flush_pending() and flush_tlb_batched_pending() are called with PTL locked, different PTL instances may be used. Because the race window is really small, and the lost TLB flushing will cause problem only if a TLB entry is inserted before the unmapping in the race window, the race is only theoretical. But the fix is simple and cheap too. Syzbot has reported this too as follows: ================================================================== BUG: KCSAN: data-race in flush_tlb_batched_pending / try_to_unmap_one write to 0xffff8881072cfbbc of 1 bytes by task 17406 on cpu 1: flush_tlb_batched_pending+0x5f/0x80 mm/rmap.c:691 madvise_free_pte_range+0xee/0x7d0 mm/madvise.c:594 walk_pmd_range mm/pagewalk.c:128 [inline] walk_pud_range mm/pagewalk.c:205 [inline] walk_p4d_range mm/pagewalk.c:240 [inline] walk_pgd_range mm/pagewalk.c:277 [inline] __walk_page_range+0x981/0x1160 mm/pagewalk.c:379 walk_page_range+0x131/0x300 mm/pagewalk.c:475 madvise_free_single_vma mm/madvise.c:734 [inline] madvise_dontneed_free mm/madvise.c:822 [inline] madvise_vma mm/madvise.c:996 [inline] do_madvise+0xe4a/0x1140 mm/madvise.c:1202 __do_sys_madvise mm/madvise.c:1228 [inline] __se_sys_madvise mm/madvise.c:1226 [inline] __x64_sys_madvise+0x5d/0x70 mm/madvise.c:1226 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae write to 0xffff8881072cfbbc of 1 bytes by task 71 on cpu 0: set_tlb_ubc_flush_pending mm/rmap.c:636 [inline] try_to_unmap_one+0x60e/0x1220 mm/rmap.c:1515 rmap_walk_anon+0x2fb/0x470 mm/rmap.c:2301 try_to_unmap+0xec/0x110 shrink_page_list+0xe91/0x2620 mm/vmscan.c:1719 shrink_inactive_list+0x3fb/0x730 mm/vmscan.c:2394 shrink_list mm/vmscan.c:2621 [inline] shrink_lruvec+0x3c9/0x710 mm/vmscan.c:2940 shrink_node_memcgs+0x23e/0x410 mm/vmscan.c:3129 shrink_node+0x8f6/0x1190 mm/vmscan.c:3252 kswapd_shrink_node mm/vmscan.c:4022 [inline] balance_pgdat+0x702/0xd30 mm/vmscan.c:4213 kswapd+0x200/0x340 mm/vmscan.c:4473 kthread+0x2c7/0x2e0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 value changed: 0x01 -> 0x00 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 71 Comm: kswapd0 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== [akpm@linux-foundation.org: tweak comments] Link: https://lkml.kernel.org/r/20211201021104.126469-1-ying.huang@intel.comSigned-off-by:"Huang, Ying" <ying.huang@intel.com> Reported-by: syzbot+aa5bebed695edaccf0df@syzkaller.appspotmail.com Cc: Nadav Amit <namit@vmware.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by:
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Qi Zheng authored
Similar to slab memory allocator, for each accounted percpu object there is an extra space which is used to store obj_cgroup membership. Charge it too. [akpm@linux-foundation.org: fix layout] Link: https://lkml.kernel.org/r/20211126040606.97836-1-zhengqi.arch@bytedance.comSigned-off-by:
Qi Zheng <zhengqi.arch@bytedance.com> Acked-by:
Dennis Zhou <dennis@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Naoya Horiguchi authored
After recent soft-offline rework, error pages can be taken off from buddy allocator, but the existing unpoison_memory() does not properly undo the operation. Moreover, due to the recent change on __get_hwpoison_page(), get_page_unless_zero() is hardly called for hwpoisoned pages. So __get_hwpoison_page() highly likely returns -EBUSY (meaning to fail to grab page refcount) and unpoison just clears PG_hwpoison without releasing a refcount. That does not lead to a critical issue like kernel panic, but unpoisoned pages never get back to buddy (leaked permanently), which is not good. To (partially) fix this, we need to identify "taken off" pages from other types of hwpoisoned pages. We can't use refcount or page flags for this purpose, so a pseudo flag is defined by hacking ->private field. Someone might think that put_page() is enough to cancel taken-off pages, but the normal free path contains some operations not suitable for the current purpose, and can fire VM_BUG_ON(). Note that unpoison_memory() is now supposed to be cancel hwpoison events injected only by madvise() or /sys/devices/system/memory/{hard,soft}_offline_page, not by MCE injection, so please don't try to use unpoison when testing with MCE injection. [lkp@intel.com: report build failure for ARCH=i386] Link: https://lkml.kernel.org/r/20211115084006.3728254-4-naoya.horiguchi@linux.devSigned-off-by:Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by:
Yang Shi <shy828301@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Ding Hui <dinghui@sangfor.com.cn> Cc: Tony Luck <tony.luck@intel.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by:
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Naoya Horiguchi authored
These action_page_types are no longer used, so remove them. Link: https://lkml.kernel.org/r/20211115084006.3728254-3-naoya.horiguchi@linux.devSigned-off-by:
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Naoya Horiguchi authored
Patch series "mm/hwpoison: fix unpoison_memory()", v4. The main purpose of this series is to sync unpoison code to recent changes around how hwpoison code takes page refcount. Unpoison should work or simply fail (without crash) if impossible. The recent works of keeping hwpoison pages in shmem pagecache introduce a new state of hwpoisoned pages, but unpoison for such pages is not supported yet with this series. It seems that soft-offline and unpoison can be used as general purpose page offline/online mechanism (not in the context of memory error). I think that we need some additional works to realize it because currently soft-offline and unpoison are assumed not to happen so frequently (print out too many messages for aggressive usecases). But anyway this could be another interesting next topic. v1: https://lore.kernel.org/linux-mm/20210614021212.223326-1-nao.horiguchi@gmail.com/ v2: https://lore.kernel.org/linux-mm/20211025230503.2650970-1-naoya.horiguchi@linux.dev/ v3: https://lore.kernel.org/linux-mm/20211105055058.3152564-1-naoya.horiguchi@linux.dev/ This patch (of 3): Originally mf_mutex is introduced to serialize multiple MCE events, but it is not that useful to allow unpoison to run in parallel with memory_failure() and soft offline. So apply mf_mutex to soft offline and unpoison. The memory failure handler and soft offline handler get simpler with this. Link: https://lkml.kernel.org/r/20211115084006.3728254-1-naoya.horiguchi@linux.dev Link: https://lkml.kernel.org/r/20211115084006.3728254-2-naoya.horiguchi@linux.devSigned-off-by:
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Nanyong Sun authored
When under the stress of swapping in/out with KSM enabled, there is a low probability that kasan reports the BUG of use-after-free in ksm_might_need_to_copy() when do swap in. The freed object is the anon_vma got from page_anon_vma(page). It is because a swapcache page associated with one anon_vma now needed for another anon_vma, but the page's original vma was unmapped and the anon_vma was freed. In this case the if condition below always return false and then alloc a new page to copy. Swapin process then use the new page and can continue to run well, so this is harmless actually. } else if (anon_vma->root == vma->anon_vma->root && page->index == linear_page_index(vma, address)) { This patch exchange the order of above two judgment statement to avoid the kasan warning. Let cpu run "page->index == linear_page_index(vma, address)" firstly and return false basically to skip the read of anon_vma->root which may trigger the kasan use-after-free warning: ================================================================== BUG: KASAN: use-after-free in ksm_might_need_to_copy+0x12e/0x5b0 Read of size 8 at addr ffff88be9977dbd0 by task khugepaged/694 CPU: 8 PID: 694 Comm: khugepaged Kdump: loaded Tainted: G OE - 4.18.0.x86_64 Hardware name: 1288H V5/BC11SPSC0, BIOS 7.93 01/14/2021 Call Trace: dump_stack+0xf1/0x19b print_address_description+0x70/0x360 kasan_report+0x1b2/0x330 ksm_might_need_to_copy+0x12e/0x5b0 do_swap_page+0x452/0xe70 __collapse_huge_page_swapin+0x24b/0x720 khugepaged_scan_pmd+0xcae/0x1ff0 khugepaged+0x8ee/0xd70 kthread+0x1a2/0x1d0 ret_from_fork+0x1f/0x40 Allocated by task 2306153: kasan_kmalloc+0xa0/0xd0 kmem_cache_alloc+0xc0/0x1c0 anon_vma_clone+0xf7/0x380 anon_vma_fork+0xc0/0x390 copy_process+0x447b/0x4810 _do_fork+0x118/0x620 do_syscall_64+0x112/0x360 entry_SYSCALL_64_after_hwframe+0x65/0xca Freed by task 2306242: __kasan_slab_free+0x130/0x180 kmem_cache_free+0x78/0x1d0 unlink_anon_vmas+0x19c/0x4a0 free_pgtables+0x137/0x1b0 exit_mmap+0x133/0x320 mmput+0x15e/0x390 do_exit+0x8c5/0x1210 do_group_exit+0xb5/0x1b0 __x64_sys_exit_group+0x21/0x30 do_syscall_64+0x112/0x360 entry_SYSCALL_64_after_hwframe+0x65/0xca The buggy address belongs to the object at ffff88be9977dba0 which belongs to the cache anon_vma_chain of size 64 The buggy address is located 48 bytes inside of 64-byte region [ffff88be9977dba0, ffff88be9977dbe0) The buggy address belongs to the page: page:ffffea00fa65df40 count:1 mapcount:0 mapping:ffff888107717800 index:0x0 flags: 0x17ffffc0000100(slab) ================================================================== Link: https://lkml.kernel.org/r/20211202102940.1069634-1-sunnanyong@huawei.comSigned-off-by:Nanyong Sun <sunnanyong@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by:
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Anshuman Khandual authored
The trace events hugepage_[invalidate|splitting], were added via the commit 9e813308 ("powerpc/thp: Add tracepoints to track hugepage invalidate"). Afterwards their call sites i.e trace_hugepage_[invalidate|splitting] were just dropped off, leaving these trace points unused. Link: https://lkml.kernel.org/r/1641546351-15109-1-git-send-email-anshuman.khandual@arm.comSigned-off-by:
Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by:
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