From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Ingo Molnar <mingo@elte.hu>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>,
paul@paulmenage.org, rjw@sisk.pl, tj@kernel.org,
frank.rowand@am.sony.com, pjt@google.com, tglx@linutronix.de,
lizf@cn.fujitsu.com, prashanth@linux.vnet.ibm.com,
paulmck@linux.vnet.ibm.com, vatsa@linux.vnet.ibm.com,
linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>
Subject: Re: [PATCH 0/4] CPU hotplug, cpusets: Fix CPU online handling related to cpusets
Date: Fri, 10 Feb 2012 16:52:07 +0100 [thread overview]
Message-ID: <1328889127.25989.14.camel@laptop> (raw)
In-Reply-To: <20120209151158.GA22489@elte.hu>
On Thu, 2012-02-09 at 16:11 +0100, Ingo Molnar wrote:
> > My understanding of the code is that when a CPU is taken
> > offline, it is removed from all the cpusets and then the
> > scan_for_empty_cpusets() function is run to move tasks from
> > empty cpusets to their parent cpusets.
>
> Why is that done that way? offlining a CPU should be an
> invariant as far as cpusets are concerned.
Can't, tasks need to run someplace. There's two choices, add a still
online cpu to the now empty cpuset or move the tasks to a parent that
still has online cpus.
Both are destructive.
next prev parent reply other threads:[~2012-02-10 15:52 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-07 18:55 [PATCH 0/4] CPU hotplug, cpusets: Fix CPU online handling related to cpusets Srivatsa S. Bhat
2012-02-07 18:56 ` [PATCH 1/4] CPU hotplug, cpuset: Maintain a copy of the cpus_allowed mask before CPU hotplug Srivatsa S. Bhat
2012-02-07 18:56 ` [PATCH 2/4] cpuset: Split up update_cpumask() so that its functionality can be reused Srivatsa S. Bhat
2012-02-07 18:57 ` [PATCH 3/4] cpuset: Add function to introduce CPUs to cpusets during CPU online Srivatsa S. Bhat
2012-02-07 18:57 ` [PATCH 4/4] CPU hotplug, cpusets: Differentiate the CPU online and CPU offline callbacks Srivatsa S. Bhat
2012-02-08 3:22 ` [PATCH 0/4] CPU hotplug, cpusets: Fix CPU online handling related to cpusets Peter Zijlstra
2012-02-08 6:33 ` Srivatsa S. Bhat
2012-02-09 7:57 ` Ingo Molnar
2012-02-09 8:42 ` Srivatsa S. Bhat
2012-02-09 15:11 ` Ingo Molnar
2012-02-10 15:52 ` Peter Zijlstra [this message]
2012-02-10 16:53 ` Paul E. McKenney
2012-02-10 17:34 ` Peter Zijlstra
2012-02-10 21:51 ` Alan Stern
2012-02-10 22:39 ` Rafael J. Wysocki
2012-02-11 2:07 ` Peter Zijlstra
2012-02-11 4:26 ` Srivatsa S. Bhat
2012-02-13 17:47 ` Srivatsa S. Bhat
2012-02-17 12:15 ` Srivatsa S. Bhat
2012-02-20 12:49 ` Peter Zijlstra
2012-02-20 12:59 ` Srivatsa S. Bhat
2012-02-23 9:57 ` Srivatsa S. Bhat
2012-02-24 23:24 ` Rafael J. Wysocki
2012-02-27 10:18 ` Peter Zijlstra
2012-02-27 12:09 ` [tip:sched/urgent] CPU hotplug, cpusets, suspend: Don' t touch cpusets during suspend/resume tip-bot for Srivatsa S. Bhat
2012-02-11 16:00 ` [PATCH 0/4] CPU hotplug, cpusets: Fix CPU online handling related to cpusets Paul E. McKenney
2012-02-13 17:47 ` Srivatsa S. Bhat
2012-02-13 20:39 ` Paul E. McKenney
2012-02-13 20:49 ` Srivatsa S. Bhat
2012-02-11 13:39 ` Ingo Molnar
2012-02-10 15:53 ` Peter Zijlstra
2012-02-09 16:43 ` Peter Zijlstra
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