From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757888AbXK0NJE (ORCPT ); Tue, 27 Nov 2007 08:09:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755040AbXK0NIz (ORCPT ); Tue, 27 Nov 2007 08:08:55 -0500 Received: from crystal.sipsolutions.net ([195.210.38.204]:59325 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755054AbXK0NIy (ORCPT ); Tue, 27 Nov 2007 08:08:54 -0500 Subject: Re: time accounting problem (powerpc only?) From: Johannes Berg To: Paul Mackerras Cc: Linux Kernel list , linuxppc-dev list In-Reply-To: <18251.59930.30260.145217@cargo.ozlabs.ibm.com> References: <1195814816.4149.94.camel@johannes.berg> <1196094193.4149.287.camel@johannes.berg> <18251.59930.30260.145217@cargo.ozlabs.ibm.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-Zmq9eWgfEu3L6rEL1fof" Date: Tue, 27 Nov 2007 14:06:20 +0100 Message-Id: <1196168780.6058.2.camel@johannes.berg> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-Zmq9eWgfEu3L6rEL1fof Content-Type: text/plain Content-Transfer-Encoding: quoted-printable 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 --=-Zmq9eWgfEu3L6rEL1fof Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUAR0wWS6Vg1VMiehFYAQKiEQ/8CzIJN0rF3Z/YUtKOUIjHJbCIhIDH1GJM LEhnKtuX7RhS2L5cGxzxn6e8ipeNK4RBlTtYchk09AeYo1wUS+R94Is2afA+y8Fz idztJuL7w6nHy/j1QVe2+45cSLJnWMgzimko7kY3FAASUk4875zqalRkR/+AAAkg GklPh0IJALa06hXPpB6HZQCtKpQDlPoy0yWzxeUQlpl2NHDrNdScBkUhB1wzxPea 81C3j0yCp9u9S3EtfbOWezta9MerQ6ps3+J0m+3VyjzGb3HeucPwU2NA5rM8Lbkx it1Mei8hi2hgZp+HNMdcWNdQWkfJXI3D9h1jkHrvC67qRRIYpIYmidKkNp16nvHR +FFUmfFG8RkzD0Q/NykQeSR48Os3E7jDP65z/Song/9b4LHx9GUu1UunnzAY8lTg zcBF+6axcq0ycyre5TrkaOK04CBtRF+qRba4wrB/ocJXDBBujMjDCo//c9NSY3gu uV/xOEPkRNoncUrbGKIKmSd29BFoYtmKWA5tCJIaaA1FBiU6oyft3wPWc4vyWouj R+xfTWs/RtFMgujQIqr8zJ8+nm0iPc4rFvXPIwuuLEA2CLFNLCc1osWXeJ6nr1Ds JTYN9eqSOZ7ZpUhrD7Kjzvd5NP6wiUObKNHFDzinfiGX+d+oGCL5XyDQ4sO5deZ/ olDdUe6a+wo= =bllv -----END PGP SIGNATURE----- --=-Zmq9eWgfEu3L6rEL1fof--