From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clark Williams Subject: [RFC] [rt-tests] change to cyclictest behavior Date: Wed, 6 Jan 2010 13:04:00 -0600 Message-ID: <20100106130400.7f30ae55@torg> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/SJyudqVlUyknBmoKuo3cu9t"; protocol="application/pgp-signature" Cc: LKML To: RT Return-path: Received: from mx1.redhat.com ([209.132.183.28]:1865 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932494Ab0AFTEJ (ORCPT ); Wed, 6 Jan 2010 14:04:09 -0500 Sender: linux-rt-users-owner@vger.kernel.org List-ID: --Sig_/SJyudqVlUyknBmoKuo3cu9t Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable RT-ers, I have a problem with the way cyclictest sets up measurement threads, but before I went and changed things I thought I would ask if people cherished this particular behavior.=20 Currently, when cyclictest is run with multiple threads (i.e. -t option) it distributes both the sample interval and the realtime priority by adding the 'distance' parameter to the interval and decrementing the priority by one. This means if you have a distance of 500us (default), a specified RT priority of 95 and start four threads, they will be started with the following parameters: $ cyclictest -t4 -p95 Will give you: thread priority sample interval 0 95 500 1 94 1000 2 93 1500 3 92 2000 What I'd like to do is modify this logic so that when '-a' (affinity) is specified, the priority and sample interval will not be altered. I don't think there's any point in distributing the priority's and sample intervals when the measurement threads are pinned to their own CPU.=20 So: $ cyclictest -t4 -p95 -a Would have each thread at SCHED_FIFO 95 and a sample interval of 500us. Note that this behavior also occurs when the histogram (-h) option is specified). Thoughts? Clark --Sig_/SJyudqVlUyknBmoKuo3cu9t Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.12 (GNU/Linux) iEYEARECAAYFAktE3qYACgkQHyuj/+TTEp0WHACfT3omcXL1B3L7zbgH+9fluw+H /ZEAoMbgZb2cCe2HwhLnunUiYLbSO3VB =FpyC -----END PGP SIGNATURE----- --Sig_/SJyudqVlUyknBmoKuo3cu9t--