tree 1e72267221c05aff3c4455910df7a787b4beff78
parent 2963e3f7e8e3465895897a175560210120b932ac
author Jens Axboe <axboe@fb.com> 1429118243 -0600
committer Jens Axboe <axboe@fb.com> 1429118243 -0600

aio: fix serial draining in exit_aio()

exit_aio() currently serializes killing io contexts. Each context
killing ends up having to do percpu_ref_kill(), which in turns has
to wait for an RCU grace period. This can take a long time, depending
on the number of contexts. And there's no point in doing them serially,
when we could be waiting for all of them in one fell swoop.

This patches makes my fio thread offload test case exit 0.2s instead
of almost 6s.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>