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| author | Pavel Begunkov <asml.silence@gmail.com> | 2022-11-30 16:21:52 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-11-30 18:26:57 +0100 |
| commit | 9805fa2d94993e16efd0e1adbd2b54d8d1fe2f9f (patch) | |
| tree | 880afb7c19c4898443ce7cad847df4a63d797133 | |
| parent | io_uring: kill io_poll_issue's PF_EXITING check (diff) | |
| download | linux-9805fa2d94993e16efd0e1adbd2b54d8d1fe2f9f.tar.xz linux-9805fa2d94993e16efd0e1adbd2b54d8d1fe2f9f.zip | |
io_uring: carve io_poll_check_events fast path
The fast path in io_poll_check_events() is when we have only one
(i.e. master) reference. Move all verification, cancellations
checks, edge case handling and so on under a common if.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8c21c5d5e027e32dc553705e88796dec79ff6f93.1669821213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | io_uring/poll.c | 41 |
1 files changed, 22 insertions, 19 deletions
diff --git a/io_uring/poll.c b/io_uring/poll.c index 599ba28c89b2..8987e13d302e 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -247,27 +247,30 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked) do { v = atomic_read(&req->poll_refs); - /* tw handler should be the owner, and so have some references */ - if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK))) - return IOU_POLL_DONE; - if (v & IO_POLL_CANCEL_FLAG) - return -ECANCELED; - /* - * cqe.res contains only events of the first wake up - * and all others are be lost. Redo vfs_poll() to get - * up to date state. - */ - if ((v & IO_POLL_REF_MASK) != 1) - req->cqe.res = 0; - if (v & IO_POLL_RETRY_FLAG) { - req->cqe.res = 0; + if (unlikely(v != 1)) { + /* tw should be the owner and so have some refs */ + if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK))) + return IOU_POLL_DONE; + if (v & IO_POLL_CANCEL_FLAG) + return -ECANCELED; /* - * We won't find new events that came in between - * vfs_poll and the ref put unless we clear the flag - * in advance. + * cqe.res contains only events of the first wake up + * and all others are to be lost. Redo vfs_poll() to get + * up to date state. */ - atomic_andnot(IO_POLL_RETRY_FLAG, &req->poll_refs); - v &= ~IO_POLL_RETRY_FLAG; + if ((v & IO_POLL_REF_MASK) != 1) + req->cqe.res = 0; + + if (v & IO_POLL_RETRY_FLAG) { + req->cqe.res = 0; + /* + * We won't find new events that came in between + * vfs_poll and the ref put unless we clear the + * flag in advance. + */ + atomic_andnot(IO_POLL_RETRY_FLAG, &req->poll_refs); + v &= ~IO_POLL_RETRY_FLAG; + } } /* the mask was stashed in __io_poll_execute */ |