From: Alex Shi <alex.shi@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: hpa@linux.intel.com, tim.c.chen@linux.intel.com,
linux-kernel@vger.kernel.org, andi.kleen@intel.com,
a.p.zijlstra@chello.nl, mingo@elte.hu
Subject: Re: [PATCH 3/3] clocksource: fix can not set tsc as clocksource bug
Date: Fri, 05 Jul 2013 14:44:24 +0800 [thread overview]
Message-ID: <51D66B48.4010205@intel.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1307050732330.11637@ionos.tec.linutronix.de>
On 07/05/2013 01:41 PM, Thomas Gleixner wrote:
>>>>> > >> > Unlikely, but if we have 3 watched clocksources which have the HRES
>>>>> > >> > bit set, you'd call 3 times clocksource_select().
>>> > > Also the reselect must be called outside the watchdog_lock region.
>> >
>> > Sorry for stupid, the watchdog_lock used protect watchdog related
>> > resource. but clocksource_select doesn't touch them. So, I know it isn't
>> > necessary to put reselect under this lock. Just don't know why the
>> > reselect *must* be called outside of it?
> clocksource_select()
> timekeeping_notify()
> stop_machine()
> get_online_cpus()
> might_sleep()
> mutex_lock()
>
> So we need to be in preemptible context when we call clocksource_select().
understand! many thanks!
--
Thanks
Alex
next prev parent reply other threads:[~2013-07-05 6:45 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-04 5:34 [URGENT rfc patch 0/3] tsc clocksource bug fix Alex Shi
2013-07-04 5:34 ` [PATCH 1/3] clocksource: clean up clocksource_select Alex Shi
2013-07-04 9:57 ` Thomas Gleixner
2013-07-04 10:21 ` Alex Shi
2013-07-04 10:27 ` Thomas Gleixner
2013-07-05 1:22 ` Alex Shi
2013-07-04 5:34 ` [PATCH 2/3] clockesource: set override clocksource Alex Shi
2013-07-04 10:23 ` Thomas Gleixner
2013-07-04 5:34 ` [PATCH 3/3] clocksource: fix can not set tsc as clocksource bug Alex Shi
2013-07-04 10:55 ` Thomas Gleixner
2013-07-04 13:04 ` Thomas Gleixner
2013-07-04 20:46 ` [PATCH] clocksource: Reselect clocksource when watchdog validated Thomas Gleixner
2013-07-05 1:38 ` Alex Shi
2013-07-05 9:13 ` [tip:timers/core] clocksource: Reselect clocksource when watchdog validated high-res capability tip-bot for Thomas Gleixner
2013-07-05 2:48 ` [PATCH 3/3] clocksource: fix can not set tsc as clocksource bug Alex Shi
2013-07-05 5:41 ` Thomas Gleixner
2013-07-05 6:44 ` Alex Shi [this message]
2013-07-04 7:58 ` [URGENT rfc patch 0/3] tsc clocksource bug fix Peter Zijlstra
2013-07-04 8:13 ` Alex Shi
2013-07-05 14:23 ` Frederic Weisbecker
2013-07-05 14:38 ` Peter Zijlstra
2013-07-05 15:24 ` Thomas Gleixner
2013-07-05 21:22 ` Peter Zijlstra
2013-07-05 21:50 ` Thomas Gleixner
2013-07-05 21:58 ` Borislav Petkov
2013-07-05 22:17 ` Thomas Gleixner
2013-07-06 8:37 ` Borislav Petkov
2013-07-06 10:50 ` Peter Zijlstra
2013-07-04 11:00 ` Thomas Gleixner
2013-07-04 18:11 ` Davidlohr Bueso
2013-07-04 20:27 ` Thomas Gleixner
2013-07-05 1:12 ` Alex Shi
2013-07-05 5:58 ` Thomas Gleixner
2013-07-05 6:28 ` Alex Shi
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