[PATCH 1/1] io_uring: don't duplicate flushing in io_req_post_cqe

[PATCH 1/1] io_uring: don't duplicate flushing in io_req_post_cqe

[Pavel Begunkov]

io_req_post_cqe() sets submit_state.cq_flush so that
*flush_completions() can take care of batch commiting CQEs. Don't commit
it twice by using __io_cq_unlock_post().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/io_uring.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 0dc6c2f1295e..7099b488c5e1 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -873,10 +873,15 @@ bool io_req_post_cqe(struct io_kiocb *req, s32 res, u32 cflags)
 	lockdep_assert(!io_wq_current_is_worker());
 	lockdep_assert_held(&ctx->uring_lock);
 
-	__io_cq_lock(ctx);
-	posted = io_fill_cqe_aux(ctx, req->cqe.user_data, res, cflags);
+	if (!ctx->lockless_cq) {
+		spin_lock(&ctx->completion_lock);
+		posted = io_fill_cqe_aux(ctx, req->cqe.user_data, res, cflags);
+		spin_unlock(&ctx->completion_lock);
+	} else {
+		posted = io_fill_cqe_aux(ctx, req->cqe.user_data, res, cflags);
+	}
+
 	ctx->submit_state.cq_flush = true;
-	__io_cq_unlock_post(ctx);
 	return posted;
 }
 
-- 
2.48.1

Re: [PATCH 1/1] io_uring: don't duplicate flushing in io_req_post_cqe

[Jens Axboe]

On Thu, 24 Apr 2025 12:28:39 +0100, Pavel Begunkov wrote:
> io_req_post_cqe() sets submit_state.cq_flush so that
> *flush_completions() can take care of batch commiting CQEs. Don't commit
> it twice by using __io_cq_unlock_post().
> 
> 

Applied, thanks!

[1/1] io_uring: don't duplicate flushing in io_req_post_cqe
      (no commit info)

Best regards,
-- 
Jens Axboe