All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mateusz Guzik <mjguzik@gmail.com>
To: brauner@kernel.org
Cc: viro@zeniv.linux.org.uk, jack@suse.cz,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Mateusz Guzik <mjguzik@gmail.com>
Subject: [PATCH] fs: tidy up do_sys_openat2() with likely/unlikely
Date: Thu, 20 Mar 2025 10:23:31 +0100	[thread overview]
Message-ID: <20250320092331.1921700-1-mjguzik@gmail.com> (raw)

Otherwise gcc 13 generates conditional forward jumps (aka branch
mispredict by default) for build_open_flags() being succesfull.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
---

maybe i'll get around to do it a full pass instead of sending byte-sized
patchen. someone(tm) should definitely do it.

 fs/open.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/open.c b/fs/open.c
index bdbf03f799a1..a9063cca9911 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1413,18 +1413,19 @@ static int do_sys_openat2(int dfd, const char __user *filename,
 			  struct open_how *how)
 {
 	struct open_flags op;
-	int fd = build_open_flags(how, &op);
 	struct filename *tmp;
+	int err, fd;
 
-	if (fd)
-		return fd;
+	err = build_open_flags(how, &op);
+	if (unlikely(err))
+		return err;
 
 	tmp = getname(filename);
 	if (IS_ERR(tmp))
 		return PTR_ERR(tmp);
 
 	fd = get_unused_fd_flags(how->flags);
-	if (fd >= 0) {
+	if (likely(fd >= 0)) {
 		struct file *f = do_filp_open(dfd, tmp, &op);
 		if (IS_ERR(f)) {
 			put_unused_fd(fd);
-- 
2.43.0


             reply	other threads:[~2025-03-20  9:23 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-20  9:23 Mateusz Guzik [this message]
2025-03-20  9:42 ` [PATCH] fs: tidy up do_sys_openat2() with likely/unlikely Christian Brauner
2025-03-20 10:49 ` Jan Kara

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=20250320092331.1921700-1-mjguzik@gmail.com \
    --to=mjguzik@gmail.com \
    --cc=brauner@kernel.org \
    --cc=jack@suse.cz \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=viro@zeniv.linux.org.uk \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.