From: Oleg Nesterov <oleg@tv-sign.ru>
To: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Paul Menage <menage@google.com>, Paul Jackson <pj@sgi.com>,
linux-kernel@vger.kernel.org
Subject: Re: [patch] sched: prevent bound kthreads from changing cpus_allowed
Date: Tue, 10 Jun 2008 21:47:50 +0400 [thread overview]
Message-ID: <20080610174750.GA6064@tv-sign.ru> (raw)
In-Reply-To: <alpine.DEB.1.10.0806051255500.31157@chino.kir.corp.google.com>
On 06/05, David Rientjes wrote:
>
> Kthreads that have called kthread_bind() are bound to specific cpus, so
> other tasks should not be able to change their cpus_allowed from under
> them. Otherwise, it is possible to move kthreads, such as the migration
> or software watchdog threads, so they are not allowed access to the cpu
> they work on.
Imho, this is very good change, but...
> @@ -180,6 +180,7 @@ void kthread_bind(struct task_struct *k, unsigned int cpu)
> set_task_cpu(k, cpu);
> k->cpus_allowed = cpumask_of_cpu(cpu);
> k->rt.nr_cpus_allowed = 1;
> + k->flags |= PF_THREAD_BOUND;
What if user-space moves this task right before "|= PF_THREAD_BOUND" ?
Oleg.
prev parent reply other threads:[~2008-06-10 17:46 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-05 19:57 David Rientjes
2008-06-05 20:29 ` Paul Jackson
2008-06-05 21:12 ` David Rientjes
2008-06-09 20:59 ` Max Krasnyanskiy
2008-06-09 22:07 ` David Rientjes
2008-06-10 4:23 ` Max Krasnyansky
2008-06-10 17:04 ` David Rientjes
2008-06-10 16:30 ` cpusets and kthreads, inconsistent behaviour Max Krasnyansky
2008-06-10 18:47 ` David Rientjes
2008-06-10 20:44 ` Max Krasnyansky
2008-06-10 20:54 ` David Rientjes
2008-06-10 21:15 ` Max Krasnyansky
2008-06-10 6:44 ` [patch] sched: prevent bound kthreads from changing cpus_allowed Peter Zijlstra
2008-06-10 15:38 ` Max Krasnyansky
2008-06-10 17:00 ` Oleg Nesterov
2008-06-10 17:19 ` Peter Zijlstra
2008-06-10 20:24 ` workqueue cpu affinity Max Krasnyansky
2008-06-11 6:49 ` Peter Zijlstra
2008-06-11 19:02 ` Max Krasnyansky
2008-06-12 18:44 ` Peter Zijlstra
2008-06-12 19:10 ` Max Krasnyanskiy
2008-06-11 16:08 ` Oleg Nesterov
2008-06-11 19:21 ` Max Krasnyansky
2008-06-11 19:21 ` Max Krasnyansky
2008-06-12 16:35 ` Oleg Nesterov
2008-06-11 20:44 ` Max Krasnyansky
2008-06-10 18:00 ` [patch] sched: prevent bound kthreads from changing cpus_allowed Max Krasnyansky
2008-06-05 20:52 ` Daniel Walker
2008-06-05 21:47 ` Paul Jackson
2008-06-10 10:28 ` Ingo Molnar
2008-06-10 17:47 ` Oleg Nesterov [this message]
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