From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory Haskins Subject: Re: Cyclictest usage Date: Mon, 11 Aug 2008 08:48:23 -0400 Message-ID: <48A03517.40708@novell.com> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig85FAC988E806F78324399EFB" Cc: linux-rt-users@vger.kernel.org To: Tobias Knutsson Return-path: Received: from victor.provo.novell.com ([137.65.250.26]:35507 "EHLO victor.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751221AbYHKMuk (ORCPT ); Mon, 11 Aug 2008 08:50:40 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig85FAC988E806F78324399EFB Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Tobias Knutsson wrote: > Hello, > > I'm trying to do some initial benchmarking on a rt-kernel versus a > vanilla kernel. On the rt the results are stable in between test runs > using the following command: > > cyclictest -t 1 -p 80 -c 1 -n -i 10000 -l 10000 > > However, using the same command while running the vanilla kernel, I > get very varying results. And I would completely understand if it was > due to increased jitter. The thing is, the jitter is very low (0% > load) but the average times varies from 600 us to 6500 us depending on > when the test is initiated. > > I imagine this might have something to do with not having high res > timers in the vanilla kernel. If that is what's causing my problems. > What is the best way of comparing the two kernels? > > I would be much greatful for a few pointers! > > =20 Hi Tobias, What kernel versions are you testing out? --------------enig85FAC988E806F78324399EFB Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkigNRcACgkQlOSOBdgZUxkEYgCfY1cHbS4qKXixEecKzFAx7N2u uJUAn0Mbh1a0eF90DGROHjYjnPBWyEOI =d6VV -----END PGP SIGNATURE----- --------------enig85FAC988E806F78324399EFB--