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authorMichal Hocko <mhocko@suse.com>2016-05-23 16:25:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-23 17:04:14 -0700
commit7c051267931a9be9c6620cc17b362bc6ee6dedc8 (patch)
treef955cbab8e30abfc0fcd69eff3462d59c364cd5a /kernel/fork.c
parent4e80153a6044bcd9a7d65c1ec4b1d1c44ba0ed6c (diff)
downloadlinux-linaro-stable-7c051267931a9be9c6620cc17b362bc6ee6dedc8.tar.gz
mm, fork: make dup_mmap wait for mmap_sem for write killable
dup_mmap needs to lock current's mm mmap_sem for write. If the waiting task gets killed by the oom killer 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. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index e67d7b773348..47887bba944f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -414,7 +414,10 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
unsigned long charge;
uprobe_start_dup_mmap();
- down_write(&oldmm->mmap_sem);
+ if (down_write_killable(&oldmm->mmap_sem)) {
+ retval = -EINTR;
+ goto fail_uprobe_end;
+ }
flush_cache_dup_mm(oldmm);
uprobe_dup_mmap(oldmm, mm);
/*
@@ -526,6 +529,7 @@ out:
up_write(&mm->mmap_sem);
flush_tlb_mm(oldmm);
up_write(&oldmm->mmap_sem);
+fail_uprobe_end:
uprobe_end_dup_mmap();
return retval;
fail_nomem_anon_vma_fork: