Message-ID: <4B1722FD.3080807@jp.fujitsu.com>
Date: Thu, 03 Dec 2009 11:31:25 +0900
From: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
User-Agent: Thunderbird 2.0.0.23 (Windows/20090812)
MIME-Version: 1.0
To: Jan Beulich <JBeulich@novell.com>
CC: mingo@elte.hu, stable@kernel.org, tglx@linutronix.de,
       linux-kernel@vger.kernel.org, hpa@zytor.com
Subject: Re: [PATCH] x86/mce: timer must be setup unconditionally
References: <4B162A3C0200007800022F98@vpn.id2.novell.com> <4B1629A0.60403@jp.fujitsu.com> <4B1638FE0200007800022FC2@vpn.id2.novell.com>
In-Reply-To: <4B1638FE0200007800022FC2@vpn.id2.novell.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1192
Lines: 30

Jan Beulich wrote:
>>>> Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> 02.12.09 09:47 >>>
>> Jan Beulich wrote:
>>> mce_timer must be passed to setup_timer() in all cases, no matter
>>> whether it is going to be actually used. Otherwise, when the CPU gets
>>> brought down, its call to del_timer_sync() will never return, as the
>>> timer won't have a base associated, and hence lock_timer_base() will
>>> loop infinitely.
>> No, what we need to fix is hotplug callbacks.
>> So correct fix should be like "del/add timer conditionally when hotplug."
> 
> Why? This makes the logic just more complicated (you'd need to track
> whether the timer was ever setup or added), and I can't see any
> non-tolerable side effect of calling setup_timer() without ever adding
> the timer anywhere.

Ah, sorry, I mistook your patch.
It seems that I just found an another bug here...

Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>


Thanks,
H.Seto

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/