From: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri, 17 Jan 2020 00:52:46 +0000 (+0300)
Subject: io_uring: remove extra check in __io_commit_cqring
X-Git-Tag: v5.15~4609^2~20
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0791015837f1520dd72918355dcb1f1e79175255;p=platform%2Fkernel%2Flinux-starfive.git

io_uring: remove extra check in __io_commit_cqring

__io_commit_cqring() is almost always called when there is a change in
the rings, so the check is rather pessimising.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 68843a1..771954b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -860,14 +860,12 @@ static void __io_commit_cqring(struct io_ring_ctx *ctx)
 {
 	struct io_rings *rings = ctx->rings;
 
-	if (ctx->cached_cq_tail != READ_ONCE(rings->cq.tail)) {
-		/* order cqe stores with ring update */
-		smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
+	/* order cqe stores with ring update */
+	smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
 
-		if (wq_has_sleeper(&ctx->cq_wait)) {
-			wake_up_interruptible(&ctx->cq_wait);
-			kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
-		}
+	if (wq_has_sleeper(&ctx->cq_wait)) {
+		wake_up_interruptible(&ctx->cq_wait);
+		kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
 	}
 }