From 906c6caaf586180261ea581915e1cf8bc466bd69 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sun, 15 Aug 2021 10:40:26 +0100 Subject: [PATCH] io_uring: optimise io_prep_linked_timeout() Linked timeout handling during issuing is heavy, it adds extra instructions and forces to save the next linked timeout before io_issue_sqe(). Follwing the same reasoning as in refcounting patches, a request can't be freed by the time it returns from io_issue_sqe(), so now we don't need to do io_prep_linked_timeout() in advance, and it can be delayed to colder paths optimising the generic path. Also, it should also save quite a lot for requests with linked timeouts and completed inline on timeout spinlocking + hrtimer_start() + hrtimer_try_to_cancel() and so on. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/19bfc9a0d26c5c5f1e359f7650afe807ca8ef879.1628981736.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 8eea3a1e8c215..d78a05ecbf683 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1306,8 +1306,16 @@ static void io_req_track_inflight(struct io_kiocb *req) } } +static inline void io_unprep_linked_timeout(struct io_kiocb *req) +{ + req->flags &= ~REQ_F_LINK_TIMEOUT; +} + static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req) { + if (WARN_ON_ONCE(!req->link)) + return NULL; + req->flags &= ~REQ_F_ARM_LTIMEOUT; req->flags |= REQ_F_LINK_TIMEOUT; @@ -1932,6 +1940,7 @@ static bool io_disarm_next(struct io_kiocb *req) if (req->flags & REQ_F_ARM_LTIMEOUT) { struct io_kiocb *link = req->link; + req->flags &= ~REQ_F_ARM_LTIMEOUT; if (link && link->opcode == IORING_OP_LINK_TIMEOUT) { io_remove_next_linked(req); io_cqring_fill_event(link->ctx, link->user_data, @@ -6485,7 +6494,7 @@ static void io_queue_linked_timeout(struct io_kiocb *req) static void __io_queue_sqe(struct io_kiocb *req) __must_hold(&req->ctx->uring_lock) { - struct io_kiocb *linked_timeout = io_prep_linked_timeout(req); + struct io_kiocb *linked_timeout; int ret; issue_sqe: @@ -6503,10 +6512,19 @@ issue_sqe: state->compl_reqs[state->compl_nr++] = req; if (state->compl_nr == ARRAY_SIZE(state->compl_reqs)) io_submit_flush_completions(ctx); + return; } + + linked_timeout = io_prep_linked_timeout(req); + if (linked_timeout) + io_queue_linked_timeout(linked_timeout); } else if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) { + linked_timeout = io_prep_linked_timeout(req); + switch (io_arm_poll_handler(req)) { case IO_APOLL_READY: + if (linked_timeout) + io_unprep_linked_timeout(req); goto issue_sqe; case IO_APOLL_ABORTED: /* @@ -6516,11 +6534,12 @@ issue_sqe: io_queue_async_work(req); break; } + + if (linked_timeout) + io_queue_linked_timeout(linked_timeout); } else { io_req_complete_failed(req, ret); } - if (linked_timeout) - io_queue_linked_timeout(linked_timeout); } static inline void io_queue_sqe(struct io_kiocb *req) -- 2.30.2