linux-kernel - Re: [RFC PATCH] Turn off the tick even when not idle

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Message-ID: <20090903051516.GA9646@kryten>
Date:	Thu, 3 Sep 2009 15:15:16 +1000
From:	Anton Blanchard <anton@...ba.org>
To:	Josh Triplett <josh@...htriplett.org>
Cc:	linux-kernel@...r.kernel.org,
	Tim Pepper <lnxninja@...ux.vnet.ibm.com>,
	Paul McKenney <paulmck@...ux.vnet.ibm.com>,
	John Stultz <johnstul@...ibm.com>,
	Christoph Lameter <cl@...ux-foundation.org>,
	Jamey Sharp <jamey@...ilop.net>
Subject: Re: [RFC PATCH] Turn off the tick even when not idle


Hi Josh,

> The following patch (not for application any time soon) hacks away the
> timer interrupt even when not idle, by triggering the nohz mechanism
> even if not running the idle task.

Nice :) I tested it on a ppc64 box, and threw the graphs up here:

http://ozlabs.org/~anton/linux/osjitter/

With the patch applied, we saw only one interruption in the 10 second window
I measured.

Anton
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