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Subject: Re: [PATCH] Work around for periodic do_gettimeofday hang
From: Lee Revell <rlrevell@joe-job.com>
To: Arjan van de Ven <arjan@infradead.org>
Cc: Andrew Morton <akpm@osdl.org>,
       James Bottomley <James.Bottomley@SteelEye.com>,
       linux-kernel@vger.kernel.org
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Date: Sat, 27 Nov 2004 17:38:40 -0500
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On Thu, 2004-11-25 at 09:20 +0100, Arjan van de Ven wrote:
> HZ=1000 costs you 1% HPC performance, and for slower machines probably more. Also some hw (with slow smm) really doesn't likeit.

I actually profiled the timer ISR on a 600Mhz C3.  It runs for 22 usec.
So with HZ=1000 the residency of the timer interrupt is 2.2%.

Lee