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io_uring: remove check_cq checking from hot paths

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All ctx->check_cq events are slow path, don't test every single flag one
by one in the hot path, but add a common guarding if.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dff026585cea7ff3a172a7c83894a3b0111bbf6a.1655310733.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2022-06-15 17:33:55 +01:00 committed by Jens Axboe
parent aeaa72c694
commit 3a08576b96
1 changed files with 19 additions and 15 deletions
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34
io_uring/io_uring.c
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@ -1259,24 +1259,25 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
int ret = 0;
unsigned long check_cq;
check_cq = READ_ONCE(ctx->check_cq);
if (unlikely(check_cq)) {
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
__io_cqring_overflow_flush(ctx, false);
/*
* Similarly do not spin if we have not informed the user of any
* dropped CQE.
*/
if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT))
return -EBADR;
}
/*
* Don't enter poll loop if we already have events pending.
* If we do, we can potentially be spinning for commands that
* already triggered a CQE (eg in error).
*/
check_cq = READ_ONCE(ctx->check_cq);
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
__io_cqring_overflow_flush(ctx, false);
if (io_cqring_events(ctx))
return 0;
/*
* Similarly do not spin if we have not informed the user of any
* dropped CQE.
*/
if (unlikely(check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)))
return -EBADR;
do {
/*
* If a submit got punted to a workqueue, we can have the
@ -2203,12 +2204,15 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
ret = io_run_task_work_sig();
if (ret || io_should_wake(iowq))
return ret;
check_cq = READ_ONCE(ctx->check_cq);
/* let the caller flush overflows, retry */
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
return 1;
if (unlikely(check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)))
return -EBADR;
if (unlikely(check_cq)) {
/* let the caller flush overflows, retry */
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
return 1;
if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT))
return -EBADR;
}
if (!schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS))
return -ETIME;
return 1;