From: Tejun Heo <tj@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: tglx@linutronix.de, mingo@elte.hu, avi@redhat.com, efault@gmx.de,
rusty@rustcorp.com.au, linux-kernel@vger.kernel.org,
Gautham R Shenoy <ego@in.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 4/7] sched: implement force_cpus_allowed()
Date: Mon, 07 Dec 2009 20:07:20 +0900 [thread overview]
Message-ID: <4B1CE1E8.2070803@kernel.org> (raw)
In-Reply-To: <1260183278.8223.1500.camel@laptop>
Hello,
On 12/07/2009 07:54 PM, Peter Zijlstra wrote:
> So we seem to do cleanup_workqueue_thread() from CPU_POST_DEAD, but at
> that time any thread that might still be around will most certainly not
> be running on the offlined cpu anymore.
>
> If you really want to ensure you remain on the cpu, you have to complete
> from CPU_DOWN_PREPARE.
>
> We're not running things from offline CPUs.
Oh, no, we're not doing that. We can't do that. What we're doing is
to continue to process works which were queued on the now offline cpu
unless it has been flushed/cancled from one of the cpu down
notifications and the reason why we need to be able to fork after
active is clear is to guarantee those flush/cancels don't deadlock.
Thanks.
--
tejun
next prev parent reply other threads:[~2009-12-07 11:07 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-02 3:56 [PATCHSET tip/sched/core] sched: concurrency managed workqueue related sched patches Tejun Heo
2009-12-02 3:56 ` [PATCH 1/7] sched: revert 498657a478c60be092208422fefa9c7b248729c2 Tejun Heo
2009-12-02 10:42 ` [tip:sched/core] sched: Revert 498657a478c60be092208422fefa9c7b248729c2 tip-bot for Tejun Heo
2009-12-02 3:56 ` [PATCH 2/7] sched: rename preempt_notifiers to sched_notifiers and refactor implementation Tejun Heo
2009-12-02 3:56 ` [PATCH 3/7] sched: refactor try_to_wake_up() Tejun Heo
2009-12-02 9:05 ` Mike Galbraith
2009-12-02 9:51 ` Tejun Heo
2009-12-02 10:10 ` Mike Galbraith
2009-12-02 10:14 ` Tejun Heo
2009-12-02 11:01 ` Peter Zijlstra
2009-12-03 6:11 ` [PATCH UDPATED " Tejun Heo
2009-12-02 3:56 ` [PATCH 4/7] sched: implement force_cpus_allowed() Tejun Heo
2009-12-04 10:40 ` Peter Zijlstra
2009-12-04 10:43 ` Peter Zijlstra
2009-12-07 4:34 ` Tejun Heo
2009-12-07 8:35 ` Peter Zijlstra
2009-12-07 10:34 ` Tejun Heo
2009-12-07 10:54 ` Peter Zijlstra
2009-12-07 11:07 ` Tejun Heo [this message]
2009-12-08 8:41 ` Tejun Heo
2009-12-08 9:02 ` Peter Zijlstra
2009-12-08 9:12 ` Tejun Heo
2009-12-08 10:34 ` Peter Zijlstra
2009-12-08 10:38 ` Peter Zijlstra
2009-12-08 11:26 ` Tejun Heo
2009-12-08 11:24 ` Tejun Heo
2009-12-08 11:48 ` Peter Zijlstra
2009-12-08 11:56 ` Tejun Heo
2009-12-08 12:10 ` Peter Zijlstra
2009-12-08 12:23 ` Tejun Heo
2009-12-08 13:35 ` Peter Zijlstra
2009-12-09 5:25 ` Tejun Heo
2009-12-09 7:41 ` Peter Zijlstra
2009-12-09 8:03 ` Tejun Heo
2009-12-02 3:56 ` [PATCH 5/7] sched: make sched_notifiers unconditional Tejun Heo
2009-12-02 3:56 ` [PATCH 6/7] sched: add wakeup/sleep sched_notifiers and allow NULL notifier ops Tejun Heo
2009-12-02 3:56 ` [PATCH 7/7] sched: implement try_to_wake_up_local() Tejun Heo
2009-12-03 6:13 ` [PATCH UPDATED " Tejun Heo
2009-12-04 10:47 ` Peter Zijlstra
2009-12-07 3:31 ` Tejun Heo
2009-12-04 10:44 ` [PATCH " Peter Zijlstra
2009-12-07 3:26 ` Tejun Heo
2009-12-07 8:50 ` Peter Zijlstra
2009-12-07 8:56 ` Peter Zijlstra
2009-12-07 10:27 ` Tejun Heo
2009-12-08 8:53 ` Peter Zijlstra
2009-12-08 9:16 ` Tejun Heo
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