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authorMichal Hocko <mhocko@suse.com>2016-05-23 16:25:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-23 17:04:14 -0700
commit013373e8b86735086ac86aff782637f7e58ff84d (patch)
tree107ef7dc257db07c4b8ab2d34e91d0e1b606bd21
parent4136c26b65d12d0c5ef58b7d30dc0aa2a11ed491 (diff)
downloadlinux-013373e8b86735086ac86aff782637f7e58ff84d.tar.bz2
aio: make aio_setup_ring killable
aio_setup_ring waits for mmap_sem in writable mode. 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. This will also expedite the return to the userspace and do_exit. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Benamin LaHaise <bcrl@kvack.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/aio.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/aio.c b/fs/aio.c
index a6deaa78326d..fb8e45b88cd4 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -496,7 +496,12 @@ static int aio_setup_ring(struct kioctx *ctx)
ctx->mmap_size = nr_pages * PAGE_SIZE;
pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
- down_write(&mm->mmap_sem);
+ if (down_write_killable(&mm->mmap_sem)) {
+ ctx->mmap_size = 0;
+ aio_free_ring(ctx);
+ return -EINTR;
+ }
+
ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size,
PROT_READ | PROT_WRITE,
MAP_SHARED, 0, &unused);