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: Tue, 08 Dec 2009 18:12:59 +0900 [thread overview]
Message-ID: <4B1E189B.1070204@kernel.org> (raw)
In-Reply-To: <1260262963.3935.1002.camel@laptop>
Hello,
On 12/08/2009 06:02 PM, Peter Zijlstra wrote:
> So its only needed in order to flush a workqueue from CPU_DOWN_PREPARE?
> And all you need it to place a new kthread on a !active cpu?
Yes, that's all I need.
> Or is this in order to allow migrate_live_tasks() to move the worker
> threads away from the dead cpu?
Nope, that's left to sched cpu callbacks.
> I'm really not thrilled by the whole fork-fest workqueue design.
Shared work pool kind of needs forks unless it's gonna create all the
workers upfront. Most issues arise from corner cases - deadlocks, cpu
hotplugging, freeze/thaw and so on. During usual operation, the
thread pool would remain largely stable.
Thanks.
--
tejun
next prev parent reply other threads:[~2009-12-08 9:12 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
2009-12-08 8:41 ` Tejun Heo
2009-12-08 9:02 ` Peter Zijlstra
2009-12-08 9:12 ` Tejun Heo [this message]
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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