io-uring.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Noah Goldstein <goldstein.w.n@gmail.com>
To: unlisted-recipients:; (no To-header on input)
Cc: goldstein.w.n@gmail.com, axboe@kernel.dk, asml.silence@gmail.com,
	io-uring@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1] fs/io_uring: Prioritise checking faster conditions first in io_write
Date: Sat, 16 Oct 2021 20:32:29 -0500	[thread overview]
Message-ID: <20211017013229.4124279-1-goldstein.w.n@gmail.com> (raw)

This commit reorders the conditions in a branch in io_write. The
reorder to check 'ret2 == -EAGAIN' first as checking
'(req->ctx->flags & IORING_SETUP_IOPOLL)' will likely be more
expensive due to 2x memory derefences.

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
---
 fs/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 6b9e70208782..321de7ddf2cf 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3660,7 +3660,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
 		goto done;
 	if (!force_nonblock || ret2 != -EAGAIN) {
 		/* IOPOLL retry should happen for io-wq threads */
-		if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
+		if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL))
 			goto copy_iov;
 done:
 		kiocb_done(kiocb, ret2, issue_flags);
-- 
2.25.1


             reply	other threads:[~2021-10-17  1:32 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-17  1:32 Noah Goldstein [this message]
2021-10-17 14:23 ` [PATCH v1] fs/io_uring: Prioritise checking faster conditions first in io_write Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211017013229.4124279-1-goldstein.w.n@gmail.com \
    --to=goldstein.w.n@gmail.com \
    --cc=asml.silence@gmail.com \
    --cc=axboe@kernel.dk \
    --cc=io-uring@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).