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From: Nick Piggin <nickpiggin@yahoo.com.au>
To: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: bug in sched.c:activate_task()
Date: Tue, 05 Oct 2004 16:10:41 +1000	[thread overview]
Message-ID: <41623AE1.2010202@yahoo.com.au> (raw)
In-Reply-To: <200410050216.i952Gb620657@unix-os.sc.intel.com>

Chen, Kenneth W wrote:
> 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>
> 

Actually, now that I have the code in front of me, I was wrong
and this patch is right.

This timestamp is never used for anything, so the assignment is
pointless.

  parent reply	other threads:[~2004-10-05  6:10 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-10-05  2:16 bug in sched.c:activate_task() Chen, Kenneth W
2004-10-05  2:34 ` 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 [this message]
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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