From 51d48dab62ed9e44e0ccc723411b0d95286a821c Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Mon, 4 Oct 2021 20:02:47 +0100
Subject: [PATCH] io_uring: add more likely/unlikely() annotations
Git-commit: 51d48dab62ed9e44e0ccc723411b0d95286a821c
Patch-mainline: v5.16-rc1
References: bsc#1205205
Add two extra unlikely() in io_submit_sqes() and one around
io_req_needs_clean() to help the compiler to avoid extra jumps
in hot paths.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/88e087afe657e7660194353aada9b00f11d480f9.1633373302.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
fs/io_uring.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index ab07a0813f20..bc87ed85f206 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1957,7 +1957,7 @@ static inline void io_dismantle_req(struct io_kiocb *req)
{
unsigned int flags = req->flags;
- if (io_req_needs_clean(req))
+ if (unlikely(io_req_needs_clean(req)))
io_clean_op(req);
if (!(flags & REQ_F_FIXED_FILE))
io_put_file(req->file);
@@ -7198,11 +7198,11 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
unsigned int entries = io_sqring_entries(ctx);
int submitted = 0;
- if (!entries)
+ if (unlikely(!entries))
return 0;
/* make sure SQ entry isn't read before tail */
nr = min3(nr, ctx->sq_entries, entries);
- if (!percpu_ref_tryget_many(&ctx->refs, nr))
+ if (unlikely(!percpu_ref_tryget_many(&ctx->refs, nr)))
return -EAGAIN;
io_get_task_refs(nr);
--
2.35.3