diff options
| author | Dylan Yudaken <dylany@meta.com> | 2022-11-24 01:35:55 -0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-11-25 06:10:04 -0700 |
| commit | 9b8c54755a2b16d4f23c0ea184b75e2edf77d906 (patch) | |
| tree | f5084117ac5bfeca0b7ce2c50b8d276411bc5f6e /io_uring/poll.c | |
| parent | 931147ddfa6e9ffd814272f1c0370c4740acbe17 (diff) | |
io_uring: add io_aux_cqe which allows deferred completion
Use the just introduced deferred post cqe completion state when possible
in io_aux_cqe. If not possible fallback to io_post_aux_cqe.
This introduces a complication because of allow_overflow. For deferred
completions we cannot know without locking the completion_lock if it will
overflow (and even if we locked it, another post could sneak in and cause
this cqe to be in overflow).
However since overflow protection is mostly a best effort defence in depth
to prevent infinite loops of CQEs for poll, just checking the overflow bit
is going to be good enough and will result in at most 16 (array size of
deferred cqes) overflows.
Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Dylan Yudaken <dylany@meta.com>
Link: https://lore.kernel.org/r/20221124093559.3780686-6-dylany@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/poll.c')
| -rw-r--r-- | io_uring/poll.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/io_uring/poll.c b/io_uring/poll.c index 4bd43e6f5b72..922c1a366c41 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -252,8 +252,8 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) __poll_t mask = mangle_poll(req->cqe.res & req->apoll_events); - if (!io_post_aux_cqe(ctx, req->cqe.user_data, - mask, IORING_CQE_F_MORE, false)) { + if (!io_aux_cqe(ctx, *locked, req->cqe.user_data, + mask, IORING_CQE_F_MORE, false)) { io_req_set_res(req, mask, 0); return IOU_POLL_REMOVE_POLL_USE_RES; } |