Michal Hocko <[email protected]> writes: > From: Michal Hocko <[email protected]> > > 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. > > Cc: Benjamin LaHaise <[email protected]> > Cc: Alexander Viro <[email protected]> > Signed-off-by: Michal Hocko <[email protected]> > --- > fs/aio.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/fs/aio.c b/fs/aio.c > index 56bcdf4105f4..1c2e7e2c1b2b 100644 > --- a/fs/aio.c > +++ b/fs/aio.c > @@ -520,7 +520,12 @@ 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);
Reviewed-by: Jeff Moyer <[email protected]>
