From 51d48dab62ed9e44e0ccc723411b0d95286a821c Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 4 Oct 2021 20:02:47 +0100 Subject: [PATCH] io_uring: add more likely/unlikely() annotations 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 Link: https://lore.kernel.org/r/88e087afe657e7660194353aada9b00f11d480f9.1633373302.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- 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 ab07a08..bc87ed8 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); -- 2.7.4