Message-ID: <1433919306.1495.55.camel@twins>
Subject: Re: [PATCH 08/14] hrtimer: Allow hrtimer::function() to free the
 timer
From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: umgwanakikbuti@gmail.com, mingo@elte.hu, ktkhai@parallels.com,
        rostedt@goodmis.org, tglx@linutronix.de, juri.lelli@gmail.com,
        pang.xunlei@linaro.org, wanpeng.li@linux.intel.com,
        linux-kernel@vger.kernel.org
Date: Wed, 10 Jun 2015 08:55:06 +0200
In-Reply-To: <20150609213318.GA12436@redhat.com>
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	 <20150608091417.GM19282@twins.programming.kicks-ass.net>
	 <20150608124234.GW18673@twins.programming.kicks-ass.net>
	 <20150609213318.GA12436@redhat.com>
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On Tue, 2015-06-09 at 23:33 +0200, Oleg Nesterov wrote:
> 
> Yes, but wmb() is cheap on x86... Perhaps we can make this code
> "obviously correct" ?

I'll reply to the rest a bit later; got to run some errands first.

The 'problem' of course is ARM/PPC etc.. we would like to keep this
generic code fast, even for the loosely ordered machines.

And wmb() is certainly not cheap for them; although not as bad as a full
barrier.
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