Date: Mon, 20 May 2013 06:50:23 +0200
From: Borislav Petkov <bp@alien8.de>
To: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Jiri Kosina <jkosina@suse.cz>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Tony Luck <tony.luck@intel.com>, linux-kernel@vger.kernel.org,
        x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: NOHZ: WARNING: at arch/x86/kernel/smp.c:123
 native_smp_send_reschedule, round 2
Message-ID: <20130520045023.GA12690@pd.tnic>
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 <20130515184528.GO4442@linux.vnet.ibm.com>
 <20130515224358.GF11783@pd.tnic>
 <20130515235512.GT4442@linux.vnet.ibm.com>
 <20130517135641.GF23035@pd.tnic>
 <51999591.8030401@linux.vnet.ibm.com>
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On Mon, May 20, 2013 at 11:16:33AM +0800, Michael Wang wrote:
> I suppose the reason is that the cpu we passed to
> mod_delayed_work_on() has a chance to become offline before we
> disabled irq, what about check it before send resched ipi? like:

I think this is only addressing the symptoms - what we should be doing
instead is asking ourselves why are we even scheduling work on a cpu if
the machine goes offline?

I don't know though who should be responsible for killing all that
work - the workqueue itself or the guy who created it, i.e. cpufreq
governor...

Hmmm.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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