From: Mike Galbraith <efault@gmx.de>
To: lkml <linux-kernel@vger.kernel.org>
Cc: Con Kolivas <kernel@kolivas.org>, Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@osdl.org>,
Nick Piggin <nickpiggin@yahoo.com.au>,
Peter Williams <pwil3058@bigpond.net.au>
Subject: [2.6.16-mm1 patch] ignore timewarps
Date: Sat, 25 Mar 2006 07:18:50 +0100 [thread overview]
Message-ID: <1143267530.9804.13.camel@homer> (raw)
In-Reply-To: <1143263172.7930.15.camel@homer>
Greetings,
The patch below is a correction to patch 1 of my throttling tree series.
The only thing that really matters is that timewarps are ignored,
whatever the cause. This patch does that, and only that.
-Mike
Signed-off-by: Mike Galbraith <efault@gmx.de>
--- linux-2.6.16-mm1/kernel/sched.c.org 2006-03-23 15:01:41.000000000 +0100
+++ linux-2.6.16-mm1/kernel/sched.c 2006-03-23 15:02:25.000000000 +0100
@@ -805,6 +805,15 @@
unsigned long long __sleep_time = now - p->timestamp;
unsigned long sleep_time;
+ /*
+ * On SMP systems, a task can go to sleep on one CPU
+ * and wake up on another. When this happens, now can
+ * end up being less than p->timestamp for short sleeps.
+ * Ignore these, they're insignificant.
+ */
+ if (unlikely(now < p->timestamp))
+ __sleep_time = 0;
+
if (batch_task(p))
sleep_time = 0;
else {
next prev parent reply other threads:[~2006-03-25 6:18 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-24 11:03 [2.6.16-mm1 patch] throttling tree patches Mike Galbraith
2006-03-24 11:07 ` Mike Galbraith
2006-03-24 11:16 ` Mike Galbraith
2006-03-24 11:21 ` Mike Galbraith
2006-03-24 11:24 ` Mike Galbraith
2006-03-24 11:28 ` Mike Galbraith
2006-03-24 11:56 ` Con Kolivas
2006-03-24 11:55 ` Con Kolivas
2006-03-24 11:54 ` Con Kolivas
2006-03-24 11:56 ` Con Kolivas
2006-03-24 12:21 ` Mike Galbraith
2006-03-24 12:34 ` Con Kolivas
2006-03-24 13:02 ` Mike Galbraith
2006-03-24 13:52 ` Con Kolivas
2006-03-24 14:10 ` Mike Galbraith
2006-03-24 11:38 ` Con Kolivas
2006-03-24 11:37 ` Con Kolivas
2006-03-25 0:25 ` Peter Williams
2006-03-25 5:06 ` Mike Galbraith
2006-03-25 6:18 ` Mike Galbraith [this message]
2006-03-25 0:37 ` Peter Williams
2006-03-25 5:11 ` Mike Galbraith
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=1143267530.9804.13.camel@homer \
--to=efault@gmx.de \
--cc=akpm@osdl.org \
--cc=kernel@kolivas.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=nickpiggin@yahoo.com.au \
--cc=pwil3058@bigpond.net.au \
/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