Commit 888aae2e authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: further deduplicate #CQ events calc 



Apparently, there is one more place hand coded calculation of number of
CQ events in the ring. Use __io_cqring_events() helper in
io_get_cqring() as well. Naturally, assembly stays identical.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ec30e04b

fs/io_uring.c

+7 −8
Original line number Diff line number Diff line
@@ -1700,21 +1700,25 @@ static inline bool io_sqring_full(struct io_ring_ctx *ctx) 
	return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries;

}



static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)

{

	return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);

}



static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)

{

	struct io_rings *rings = ctx->rings;

	unsigned tail;



	tail = ctx->cached_cq_tail;

	/*

	 * writes to the cq entry need to come after reading head; the

	 * control dependency is enough as we're using WRITE_ONCE to

	 * fill the cq entry

	 */

	if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)

	if (__io_cqring_events(ctx) == rings->cq_ring_entries)

		return NULL;



	ctx->cached_cq_tail++;

	tail = ctx->cached_cq_tail++;

	return &rings->cqes[tail & ctx->cq_mask];

}
@@ -1729,11 +1733,6 @@ static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx) 
	return io_wq_current_is_worker();

}



static inline unsigned __io_cqring_events(struct io_ring_ctx *ctx)

{

	return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);

}



static void io_cqring_ev_posted(struct io_ring_ctx *ctx)

{

	/* see waitqueue_active() comment */