mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH] sched: Remove broken check for skip clock update
Date: Tue,  8 Jan 2013 02:07:34 +0100	[thread overview]
Message-ID: <1357607254-511-1-git-send-email-fweisbec@gmail.com> (raw)

rq->skip_clock_update shouldn't be negative. Thus the check
in put_prev_task() is useless.

It was probably intended to do the following check:

	if (prev->on_rq && !rq->skip_clock_update)

We only want to update the clock if the current task is
not voluntarily sleeping: otherwise deactivate_task()
already did the rq clock update in schedule(). But we want
to ignore that update if a ttwu did it for us, in which case
rq->skip_clock_update is 1.

But update_rq_clock() already takes care of that so we
can just remove the broken condition.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/sched/core.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 15ba35e..8dfc461 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2886,7 +2886,7 @@ static inline void schedule_debug(struct task_struct *prev)
 
 static void put_prev_task(struct rq *rq, struct task_struct *prev)
 {
-	if (prev->on_rq || rq->skip_clock_update < 0)
+	if (prev->on_rq)
 		update_rq_clock(rq);
 	prev->sched_class->put_prev_task(rq, prev);
 }
-- 
1.7.5.4


             reply	other threads:[~2013-01-08  1:07 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-08  1:07 Frederic Weisbecker [this message]
2013-01-08  1:49 ` Steven Rostedt
2013-01-08  1:55   ` Frederic Weisbecker

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=1357607254-511-1-git-send-email-fweisbec@gmail.com \
    --to=fweisbec@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.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®