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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon, 13 Sep 2010 10:51:38 -0700
Message-ID: <AANLkTi=8m4g01wZPacySoF7U0PevTNVgJoZZrHiUD-pN@mail.gmail.com>
Subject: Re: [RFC PATCH] check_preempt_tick should not compare vruntime with
 wall time
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>, LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>, Ingo Molnar <mingo@elte.hu>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>, Tony Lindgren <tony@atomide.com>,
        Mike Galbraith <efault@gmx.de>
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On Mon, Sep 13, 2010 at 10:45 AM, Mathieu Desnoyers
<mathieu.desnoyers@efficios.com> wrote:
>
> FWIW, Xorg and firefox feel _much more_ responsive with the fix I propose when
> running with a make -j10. The system is even usable with a make -j20 on my UP
> machine, even though I can start feeling a some lag. This is probably a more
> important, yet less scientific, result.

I'll test that myself (but in a bit - I need to go do voter
registration and socsec update first, though - I became a US citizen
last week).

Because yes, that's the reason I'm personally interested in your
scheduler latency work: I think our X behavior under load is pitiful
(I do "make -j16" on my dual-core with HT Core i5, and web browsong
shouldn't start to lag as much as it does just because I overcommit
the CPU a bit). So if this makes a noticeable difference, I think it's
very important.

                       Linus