From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
Zhenzhong Duan <zhenzhong.duan@oracle.com>
Subject: [PATCH] sched/clock: use static_branch_likely() check at sched_clock_running
Date: Wed, 27 Nov 2019 16:37:28 +0800 [thread overview]
Message-ID: <1574843848-26825-1-git-send-email-zhenzhong.duan@oracle.com> (raw)
sched_clock_running is enabled early at bootup stage and never
disabled. So hints that to compiler by using static_branch_likely()
rather than static_branch_unlikely().
Fixes: 46457ea464f5 ("sched/clock: Use static key for sched_clock_running")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
---
kernel/sched/clock.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index 1152259..12bca64 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -370,7 +370,7 @@ u64 sched_clock_cpu(int cpu)
if (sched_clock_stable())
return sched_clock() + __sched_clock_offset;
- if (!static_branch_unlikely(&sched_clock_running))
+ if (!static_branch_likely(&sched_clock_running))
return sched_clock();
preempt_disable_notrace();
@@ -393,7 +393,7 @@ void sched_clock_tick(void)
if (sched_clock_stable())
return;
- if (!static_branch_unlikely(&sched_clock_running))
+ if (!static_branch_likely(&sched_clock_running))
return;
lockdep_assert_irqs_disabled();
@@ -460,7 +460,7 @@ void __init sched_clock_init(void)
u64 sched_clock_cpu(int cpu)
{
- if (!static_branch_unlikely(&sched_clock_running))
+ if (!static_branch_likely(&sched_clock_running))
return 0;
return sched_clock();
--
1.8.3.1
next reply other threads:[~2019-11-27 8:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-27 8:37 Zhenzhong Duan [this message]
2019-11-27 15:14 ` Steven Rostedt
2019-11-29 9:59 ` [tip: sched/urgent] sched/clock: Use static_branch_likely() with sched_clock_running tip-bot2 for Zhenzhong Duan
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=1574843848-26825-1-git-send-email-zhenzhong.duan@oracle.com \
--to=zhenzhong.duan@oracle.com \
--cc=bsegall@google.com \
--cc=dietmar.eggemann@arm.com \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@suse.de \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=vincent.guittot@linaro.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
all inboxes | Powered by JetHome®