From: Fabio Checconi <fchecconi@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
Paul Turner <pjt@google.com>,
Dario Faggioli <faggioli@gandalf.sssup.it>,
Michael Trimarchi <michael@evidence.eu.com>,
Dhaval Giani <dhaval@retis.sssup.it>,
Tommaso Cucinotta <t.cucinotta@sssup.it>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] sched: enforce per-cpu utilization limits on runtime balancing
Date: Wed, 3 Mar 2010 17:59:26 +0100 [thread overview]
Message-ID: <20100303165926.GM2490@gandalf.sssup.it> (raw)
In-Reply-To: <1267129702.22519.558.camel@laptop>
> From: Peter Zijlstra <peterz@infradead.org>
> Date: Thu, Feb 25, 2010 09:28:22PM +0100
>
> On Tue, 2010-02-23 at 19:56 +0100, Fabio Checconi wrote:
> > + /*
> > + * Make sure that before restarting balancing everyone
> > + * sees the new free bandwidth.
> > + */
> > + smp_wmb();
>
> You cannot order something on its own, barriers come in pairs, where is
> his?
It was coupled with the acquire barrier implied by the spin_lock(rt_b)
in the balance path, as the other wmb() before starting the reset (more
details on the reply about this last barrier, as per your comment they
can be removed).
next prev parent reply other threads:[~2010-03-03 16:46 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-23 18:56 [PATCH 0/3] sched: use EDF to throttle RT task groups v2 Fabio Checconi
2010-02-23 18:56 ` [PATCH 1/3] sched: use EDF to schedule groups Fabio Checconi
2010-02-25 20:28 ` Peter Zijlstra
2010-03-03 16:59 ` Fabio Checconi
2010-02-23 18:56 ` [PATCH 2/3] sched: enforce per-cpu utilization limits on runtime balancing Fabio Checconi
2010-02-25 20:28 ` Peter Zijlstra
2010-03-03 16:59 ` Fabio Checconi [this message]
2010-02-25 20:28 ` Peter Zijlstra
2010-03-03 17:00 ` Fabio Checconi
2010-03-23 20:32 ` Peter Zijlstra
2010-02-25 20:28 ` Peter Zijlstra
2010-03-03 16:59 ` Fabio Checconi
2010-02-25 20:28 ` Peter Zijlstra
2010-03-03 17:00 ` Fabio Checconi
2010-03-23 20:33 ` Peter Zijlstra
2010-02-25 20:28 ` Peter Zijlstra
2010-03-03 17:00 ` Fabio Checconi
2010-02-23 18:56 ` [PATCH 3/3] sched: make runtime balancing code more EDF-friendly Fabio Checconi
2010-02-25 20:28 ` Peter Zijlstra
2010-03-03 17:01 ` Fabio Checconi
2010-02-25 20:28 ` [PATCH 0/3] sched: use EDF to throttle RT task groups v2 Peter Zijlstra
2010-02-27 12:33 ` Peter Zijlstra
2010-03-03 17:01 ` Fabio Checconi
2010-03-23 20:30 ` Peter Zijlstra
2010-03-23 20:56 ` Dhaval Giani
2010-03-23 21:51 ` Tommaso Cucinotta
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