The patch titled Subject: mm, proc: make clear_refs killable has been added to the -mm tree. Its filename is mm-proc-make-clear_refs-killable.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-proc-make-clear_refs-killable.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-proc-make-clear_refs-killable.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm, proc: make clear_refs killable CLEAR_REFS_MM_HIWATER_RSS and CLEAR_REFS_SOFT_DIRTY are relying on mmap_sem for write. If the waiting task gets killed by the oom killer and it would operate on the current's mm it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. This will also expedite the return to the userspace and do_exit even if the mm is remote. Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Petr Cermak <petrcermak@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/task_mmu.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff -puN fs/proc/task_mmu.c~mm-proc-make-clear_refs-killable fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~mm-proc-make-clear_refs-killable +++ a/fs/proc/task_mmu.c @@ -1027,11 +1027,15 @@ static ssize_t clear_refs_write(struct f }; if (type == CLEAR_REFS_MM_HIWATER_RSS) { + if (down_write_killable(&mm->mmap_sem)) { + count = -EINTR; + goto out_mm; + } + /* * Writing 5 to /proc/pid/clear_refs resets the peak * resident set size to this mm's current rss value. */ - down_write(&mm->mmap_sem); reset_mm_hiwater_rss(mm); up_write(&mm->mmap_sem); goto out_mm; @@ -1043,7 +1047,10 @@ static ssize_t clear_refs_write(struct f if (!(vma->vm_flags & VM_SOFTDIRTY)) continue; up_read(&mm->mmap_sem); - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) { + count = -EINTR; + goto out_mm; + } for (vma = mm->mmap; vma; vma = vma->vm_next) { vma->vm_flags &= ~VM_SOFTDIRTY; vma_set_page_prot(vma); _ Patches currently in -mm which might be from mhocko@xxxxxxxx are include-linux-nodemaskh-create-next_node_in-helper-fix.patch mm-oom-move-gfp_nofs-check-to-out_of_memory.patch oom-oom_reaper-try-to-reap-tasks-which-skip-regular-oom-killer-path.patch oom-oom_reaper-try-to-reap-tasks-which-skip-regular-oom-killer-path-try-to-reap-tasks-which-skip-regular-memcg-oom-killer-path.patch mm-oom_reaper-clear-tif_memdie-for-all-tasks-queued-for-oom_reaper.patch mm-oom_reaper-clear-tif_memdie-for-all-tasks-queued-for-oom_reaper-clear-oom_reaper_list-before-clearing-tif_memdie.patch vmscan-consider-classzone_idx-in-compaction_ready.patch mm-compaction-change-compact_-constants-into-enum.patch mm-compaction-cover-all-compaction-mode-in-compact_zone.patch mm-compaction-distinguish-compact_deferred-from-compact_skipped.patch mm-compaction-distinguish-between-full-and-partial-compact_complete.patch mm-compaction-update-compaction_result-ordering.patch mm-compaction-simplify-__alloc_pages_direct_compact-feedback-interface.patch mm-compaction-abstract-compaction-feedback-to-helpers.patch mm-use-compaction-feedback-for-thp-backoff-conditions.patch mm-oom-rework-oom-detection.patch mm-throttle-on-io-only-when-there-are-too-many-dirty-and-writeback-pages.patch mm-oom-protect-costly-allocations-some-more.patch mm-consider-compaction-feedback-also-for-costly-allocation.patch mm-oom-compaction-prevent-from-should_compact_retry-looping-for-ever-for-costly-orders.patch mm-oom_reaper-hide-oom-reaped-tasks-from-oom-killer-more-carefully.patch mm-oom_reaper-do-not-mmput-synchronously-from-the-oom-reaper-context.patch mm-oom_reaper-do-not-mmput-synchronously-from-the-oom-reaper-context-fix.patch mm-make-mmap_sem-for-write-waits-killable-for-mm-syscalls.patch mm-make-vm_mmap-killable.patch mm-make-vm_munmap-killable.patch mm-aout-handle-vm_brk-failures.patch mm-elf-handle-vm_brk-error.patch mm-make-vm_brk-killable.patch mm-proc-make-clear_refs-killable.patch mm-fork-make-dup_mmap-wait-for-mmap_sem-for-write-killable.patch ipc-shm-make-shmem-attach-detach-wait-for-mmap_sem-killable.patch vdso-make-arch_setup_additional_pages-wait-for-mmap_sem-for-write-killable.patch coredump-make-coredump_wait-wait-for-mmap_sem-for-write-killable.patch aio-make-aio_setup_ring-killable.patch exec-make-exec-path-waiting-for-mmap_sem-killable.patch prctl-make-pr_set_thp_disable-wait-for-mmap_sem-killable.patch uprobes-wait-for-mmap_sem-for-write-killable.patch drm-i915-make-i915_gem_mmap_ioctl-wait-for-mmap_sem-killable.patch drm-radeon-make-radeon_mn_get-wait-for-mmap_sem-killable.patch drm-amdgpu-make-amdgpu_mn_get-wait-for-mmap_sem-killable.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html