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From: Nathan Lynch <ntl@pobox.com>
To: Matthias-Christian Ott <matthias.christian@tiscali.de>
Cc: lkml <linux-kernel@vger.kernel.org>,
	Rusty Russell <rusty@rustcorp.com.au>,
	Ingo Molnar <mingo@elte.hu>
Subject: Re: 2.6-bk: cpu hotplug + preempt = smp_processor_id warnings galore
Date: Fri, 11 Feb 2005 18:56:09 -0600	[thread overview]
Message-ID: <20050212005609.GB14499@otto> (raw)
In-Reply-To: <420D4646.4010600@tiscali.de>

On Sat, Feb 12, 2005 at 12:56:54AM +0100, Matthias-Christian Ott wrote:
> Nathan Lynch wrote:
> 
> >With 2.6.11-rc3-bk7 on ppc64 I am seeing lots of smp_processor_id
> >warnings whenever I hotplug cpus:
...
>
> Use get_cpu() (It disables preemption) or __smp_processor_id () (on a smp).

It's not necessarily that simple (ok, maybe the idle loop warning is).
But at least one of the warnings I listed appears to be caused by a
kernel thread that is normally bound to a particular cpu trying to do
normal processing on another cpu before it has stopped.  Injudicious
use of __smp_processor_id or get_cpu in this case would only obscure
the problem.


Nathan


  reply	other threads:[~2005-02-12  0:56 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-02-11 23:28 2.6-bk: cpu hotplug + preempt = smp_processor_id warnings galore Nathan Lynch
2005-02-11 23:56 ` Matthias-Christian Ott
2005-02-12  0:56   ` Nathan Lynch [this message]
2005-02-12 18:59 ` Zwane Mwaikambo
2005-02-14 21:59   ` Nathan Lynch
2005-02-15  7:02     ` Ingo Molnar
2005-02-16  2:06       ` [PATCH] kthread_bind new worker threads when onlining cpu Nathan Lynch
2005-02-16  5:31         ` [PATCH] Run softirqs on proper processor on offline Zwane Mwaikambo
2005-02-16  5:34           ` Ingo Molnar
2005-02-16  5:51           ` Andrew Morton
2005-02-16  6:17             ` Zwane Mwaikambo
2005-02-15 15:29     ` 2.6-bk: cpu hotplug + preempt = smp_processor_id warnings galore Zwane Mwaikambo
2005-02-15 17:26       ` Nathan Lynch

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