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Subject: Re: time accounting problem (powerpc only?)
From: Johannes Berg <johannes@sipsolutions.net>
To: Paul Mackerras <paulus@samba.org>
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Date: Tue, 27 Nov 2007 14:06:20 +0100
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On Tue, 2007-11-27 at 20:57 +1100, Paul Mackerras wrote:
> Johannes Berg writes:
>=20
> > Contrary to what I claimed later in the thread, my 64-bit powerpc box
> > (quad-core G5) doesn't suffer from this problem.
> >=20
> > Does anybody have any idea? I don't even know how to debug it further.
>=20
> I see it on my G4 powerbook.  However, a compute-bound task runs just
> as fast (i.e. completes in the same elapsed time) as on older kernels,
> so it does look like it is just an accounting problem.  If the CPU was
> really spending more than half its time servicing hardware interrupts,
> the task should take more than twice as long to complete.

Exactly. So where do I look for the accounting bug?

johannes

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