Date: Wed, 8 May 2013 13:15:16 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Alex Shi <alex.shi@intel.com>
Cc: Paul Turner <pjt@google.com>, Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Borislav Petkov <bp@alien8.de>, Namhyung Kim <namhyung@kernel.org>,
        Mike Galbraith <efault@gmx.de>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Preeti U Murthy <preeti@linux.vnet.ibm.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mgorman@suse.de>,
        Rik van Riel <riel@redhat.com>,
        Michael Wang <wangyun@linux.vnet.ibm.com>
Subject: Re: [PATCH v5 3/7] sched: set initial value of runnable avg for new
 forked task
Message-ID: <20130508111516.GA6803@dyad.programming.kicks-ass.net>
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On Tue, May 07, 2013 at 11:24:52AM +0800, Alex Shi wrote:
> It will give new forked task 1 ms extra running time. That will bring
> incorrect info if the new forked goes to sleep a while.
> But this info should benefit to some benchmarks like aim7,
> pthread_cond_broadcast. So I am convinced. :)
> 
> What's your opinion of this, Peter?

We're going to get it wrong anyhow (lack of crystal ball instruction);
overestimating the load seems like the best deal wrt latency for new tasks.

The only other option we could try (not sure its even worth trying) would be
half load.
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