Commit 04518945 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: separate DRAIN flushing into a cold path 



io_commit_cqring() assembly doesn't look good with extra code handling
drained requests. IOSQE_IO_DRAIN is slow and discouraged to be used in
a hot path, so try to minimise its impact by putting it into a helper
and doing a fast check.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 56080b02

fs/io_uring.c

+15 −15
Original line number Diff line number Diff line
@@ -982,19 +982,6 @@ static inline bool req_need_defer(struct io_kiocb *req) 
	return false;

}



static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)

{

	struct io_kiocb *req;



	req = list_first_entry_or_null(&ctx->defer_list, struct io_kiocb, list);

	if (req && !req_need_defer(req)) {

		list_del_init(&req->list);

		return req;

	}



	return NULL;

}



static struct io_kiocb *io_get_timeout_req(struct io_ring_ctx *ctx)

{

	struct io_kiocb *req;
@@ -1127,6 +1114,19 @@ static void io_kill_timeouts(struct io_ring_ctx *ctx) 
	spin_unlock_irq(&ctx->completion_lock);

}



static void __io_queue_deferred(struct io_ring_ctx *ctx)

{

	do {

		struct io_kiocb *req = list_first_entry(&ctx->defer_list,

							struct io_kiocb, list);



		if (req_need_defer(req))

			break;

		list_del_init(&req->list);

		io_queue_async_work(req);

	} while (!list_empty(&ctx->defer_list));

}



static void io_commit_cqring(struct io_ring_ctx *ctx)

{

	struct io_kiocb *req;
@@ -1136,8 +1136,8 @@ static void io_commit_cqring(struct io_ring_ctx *ctx) 


	__io_commit_cqring(ctx);



	while ((req = io_get_deferred_req(ctx)) != NULL)

		io_queue_async_work(req);

	if (unlikely(!list_empty(&ctx->defer_list)))

		__io_queue_deferred(ctx);

}



static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)

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