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io_uring: parse check_cq out of wq waiting

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We already avoid flushing overflows in io_cqring_wait_schedule() but
only return an error for the outer loop to handle it. Minimise it even
further by moving all ->check_cq parsing there.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9dfcec3121013f98208dbf79368d636d74e1231a.1672916894.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2023-01-05 11:22:24 +00:00 committed by Jens Axboe
parent 140102ae9a
commit 3fcf19d592
1 changed files with 18 additions and 14 deletions
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32
io_uring/io_uring.c
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@ -2471,21 +2471,13 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
ktime_t *timeout)
{
int ret;
unsigned long check_cq;
if (unlikely(READ_ONCE(ctx->check_cq)))
return 1;
/* make sure we run task_work before checking for signals */
ret = io_run_task_work_sig(ctx);
if (ret || io_should_wake(iowq))
return ret;
check_cq = READ_ONCE(ctx->check_cq);
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;
@ -2551,13 +2543,25 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
trace_io_uring_cqring_wait(ctx, min_events);
do {
if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)) {
finish_wait(&ctx->cq_wait, &iowq.wq);
io_cqring_do_overflow_flush(ctx);
}
unsigned long check_cq;
prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq,
TASK_INTERRUPTIBLE);
ret = io_cqring_wait_schedule(ctx, &iowq, &timeout);
check_cq = READ_ONCE(ctx->check_cq);
if (unlikely(check_cq)) {
/* let the caller flush overflows, retry */
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT)) {
finish_wait(&ctx->cq_wait, &iowq.wq);
io_cqring_do_overflow_flush(ctx);
}
if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) {
ret = -EBADR;
break;
}
}
if (__io_cqring_events_user(ctx) >= min_events)
break;
cond_resched();