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From: David Mosberger <davidm@napali.hpl.hp.com>
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Date: Tue, 16 Apr 2002 09:50:21 -0700
To: torvalds@transmeta.com (Linus Torvalds)
Cc: linux-kernel@vger.kernel.org
Subject: Re: Why HZ on i386 is 100 ?
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>>>>> On Tue, 16 Apr 2002 16:27:12 +0000 (UTC), torvalds@transmeta.com (Linus Torvalds) said:

  Linus> And I've had some Intel people grumble about it, because it
  Linus> apparently means that the timer tick takes anything from 2%
  Linus> to an extreme of 10% (!!) of the CPU time under certain
  Linus> loads.

I'm not sure I believe this.  I have had occasional cases where I
wondered whether the timer tick caused significant overhead, but it
always turned out to be something else.  In my measurements,
*user-level* profiling has the 2-10% overhead you're mentioning, but
that's with a signal delivered to user level on each tick.

	--david
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