From: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
To: <linux-kernel@vger.kernel.org>
Subject: bug in sched.c:activate_task()
Date: Mon, 4 Oct 2004 19:16:39 -0700 [thread overview]
Message-ID: <200410050216.i952Gb620657@unix-os.sc.intel.com> (raw)
Update p->timestamp to "now" in activate_task() doesn't look right
to me at all. p->timestamp records last time it was running on a
cpu. activate_task shouldn't update that variable when it queues
a task on the runqueue.
This bug (and combined with others) triggers improper load balancing.
Patch against linux-2.6.9-rc3. Didn't diff it against 2.6.9-rc3-mm2
because mm tree has so many change in sched.c.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
--- linux-2.6.9-rc3/kernel/sched.c.orig 2004-10-04 19:11:21.000000000 -0700
+++ linux-2.6.9-rc3/kernel/sched.c 2004-10-04 19:11:35.000000000 -0700
@@ -888,7 +888,6 @@ static void activate_task(task_t *p, run
p->activated = 1;
}
}
- p->timestamp = now;
__activate_task(p, rq);
}
next reply other threads:[~2004-10-05 2:16 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-05 2:16 Chen, Kenneth W [this message]
2004-10-05 2:34 ` bug in sched.c:activate_task() Con Kolivas
2004-10-05 3:14 ` Nick Piggin
2004-10-05 4:45 ` Con Kolivas
2004-10-05 5:05 ` Peter Williams
2004-10-05 6:10 ` Nick Piggin
2004-10-05 6:31 ` Ingo Molnar
2004-10-05 6:36 ` Con Kolivas
2004-10-05 6:54 ` Ingo Molnar
2004-10-05 6:59 ` Con Kolivas
2004-10-05 7:08 ` Nick Piggin
2004-10-05 7:09 ` Ingo Molnar
2004-10-05 17:30 ` Chen, Kenneth W
2004-10-05 17:25 ` Chen, Kenneth W
2004-10-05 6:57 ` Nick Piggin
2004-10-05 8:19 ` Ingo Molnar
2004-10-05 17:44 ` Chen, Kenneth W
-- strict thread matches above, loose matches on Subject: below --
2004-10-05 22:46 Chen, Kenneth W
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