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io_uring: thin down io_commit_cqring()

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io_commit_cqring() is currently always under spinlock section, so it's
always better to keep it as slim as possible. Move
__io_commit_cqring_flush() out of it into ev_posted*(). If fast checks
do fail and this post-processing is required, we'll reacquire
->completion_lock, which is fine as we don't care about performance of
draining and offset timeouts.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ec4e81fd720d3bc7bca8cb9152e080dad1a052f1.1647481208.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2022-03-17 02:03:41 +00:00 committed by Jens Axboe
parent 66fc25ca6b
commit 9333f6b462
1 changed files with 15 additions and 8 deletions
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23
fs/io_uring.c
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@ -1779,20 +1779,21 @@ static __cold void io_flush_timeouts(struct io_ring_ctx *ctx)
spin_unlock_irq(&ctx->timeout_lock);
}
static inline void io_commit_cqring(struct io_ring_ctx *ctx)
{
/* order cqe stores with ring update */
smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
}
static __cold void __io_commit_cqring_flush(struct io_ring_ctx *ctx)
{
spin_lock(&ctx->completion_lock);
if (ctx->off_timeout_used)
io_flush_timeouts(ctx);
if (ctx->drain_active)
io_queue_deferred(ctx);
}
static inline void io_commit_cqring(struct io_ring_ctx *ctx)
{
if (unlikely(ctx->off_timeout_used || ctx->drain_active))
__io_commit_cqring_flush(ctx);
/* order cqe stores with ring update */
smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
io_commit_cqring(ctx);
spin_unlock(&ctx->completion_lock);
}
static inline bool io_sqring_full(struct io_ring_ctx *ctx)
@ -1860,6 +1861,9 @@ static void io_eventfd_signal(struct io_ring_ctx *ctx)
*/
static inline void io_cqring_ev_posted(struct io_ring_ctx *ctx)
{
if (unlikely(ctx->off_timeout_used || ctx->drain_active))
__io_commit_cqring_flush(ctx);
/*
* wake_up_all() may seem excessive, but io_wake_function() and
* io_should_wake() handle the termination of the loop and only
@ -1873,6 +1877,9 @@ static inline void io_cqring_ev_posted(struct io_ring_ctx *ctx)
static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
{
if (unlikely(ctx->off_timeout_used || ctx->drain_active))
__io_commit_cqring_flush(ctx);
if (ctx->flags & IORING_SETUP_SQPOLL) {
if (wq_has_sleeper(&ctx->cq_wait))
wake_up_all(&ctx->cq_wait);