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Date: Sat, 25 Oct 2008 08:56:27 +0200
From: Andi Kleen <andi@firstfloor.org>
To: Mike Travis <travis@sgi.com>
Cc: Andi Kleen <andi@firstfloor.org>, Ingo Molnar <mingo@elte.hu>,
       Pavel Machek <pavel@suse.cz>, Rusty Russell <rusty@rustcorp.com.au>,
       Andrew Morton <akpm@linux-foundation.org>,
       Thomas Gleixner <tglx@linutronix.de>, Jack Steiner <steiner@sgi.com>,
       "H. Peter Anvin" <hpa@zytor.com>, Richard Purdie <rpurdie@rpsys.net>,
       LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] SGI X86 UV: Provide a System Activity Indicator	driver
Message-ID: <20081025065627.GI27492@one.firstfloor.org>
References: <4901AF28.4070606@sgi.com> <20081024120103.GD1680@elf.ucw.cz> <20081024120544.GA9812@elte.hu> <4901BF30.3090708@sgi.com> <87mygt9815.fsf@basil.nowhere.org> <490249CF.2080308@sgi.com>
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> Cool, thanks!  I rewrote the patch to use current->pid, removing the
> idle callback.

As a additional measure you could make the timer deferred when in 
idle state.  Then you would only actually do something when 
changing from idle to non idle or keeps being busy, but nothing 
when a CPU stays idle for a longer time.

The frequency wouldn't necessarily be 1 second then though.

-Andi