From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clark Williams Subject: Re: [PATCH] pip_stress: increase usleep for ARM devices Date: Wed, 10 Dec 2014 15:16:50 -0600 Message-ID: <20141210151650.1995581e@sluggy> References: <1418199901-3175-1-git-send-email-chase.qi@linaro.org> <54885564.2050904@linaro.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/F_Y0qVdHqBjTJ61MMYUYrrd"; protocol="application/pgp-signature" Cc: chase.qi@linaro.org, linux-rt-users@vger.kernel.org, milosz.wasilewski@linaro.org, naresh.kamboju@linaro.org, anders.roxell@linaro.org, mike.holmes@linaro.org, John Kacur To: Jorge Ramirez-Ortiz Return-path: Received: from mail-qg0-f42.google.com ([209.85.192.42]:63204 "EHLO mail-qg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932743AbaLJVRH (ORCPT ); Wed, 10 Dec 2014 16:17:07 -0500 Received: by mail-qg0-f42.google.com with SMTP id q108so752510qgd.15 for ; Wed, 10 Dec 2014 13:17:06 -0800 (PST) In-Reply-To: <54885564.2050904@linaro.org> Sender: linux-rt-users-owner@vger.kernel.org List-ID: --Sig_/F_Y0qVdHqBjTJ61MMYUYrrd Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Wed, 10 Dec 2014 09:15:00 -0500 Jorge Ramirez-Ortiz wrote: > On 12/10/2014 03:25 AM, chase.qi@linaro.org wrote: > > From: Chase Qi > > > > Hello, > > > > pip_stress works out of the box on my x86 based laptop, but > > doesn't work on ARM devices, returned 'no inversion incurred'. > > Follow the comment to increase usleep value, 2500 worked for > > pandaboard and 3000 worked for Beaglebone Black board. > > > > I propose that increase the usleep value to 3500 from upstream, > > so that we can use pip_stress right out of the box. > > > > Please let me know if this is acceptable. >=20 > I think they should have modified main() to accept the lock time as a par= ameter > instead of simply adding some instructions in the comments >=20 > * to show that it works. If you are having difficulty triggering an inve= rsion, > * merely increase the time that the low priority process sleeps while > * holding the lock. (usleep); > * Also note that you have to run as a user with permission to change > * scheduling priorities. > */ >=20 > what I would do is actually > 1. modify main to accept lock_time > 2. send the patch to the rt-tests team >=20 >=20 > I wish we didn't have to deal with timers here. I used barriers when I wrote pi_stress.c and obviously we don't have that luxury with pip_stress.c. I guess the best thing we can do right now is add a parameter to change the default timer value for pip_stress and see if someone comes up with a brilliant state-machine solution that will work between processes :). John and I are about to start a sweep through the tests and will probably come out with a new rt-tests around the first of the year.=20 Clark --Sig_/F_Y0qVdHqBjTJ61MMYUYrrd Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJUiLhLAAoJEEersVlSw9NzMzwP/iJ9x3kUboJ0V4lC+IO1In22 WY3kRtYoBHBCpv6y6WXS8akk64LsVIernerE67RN1a+f3zPqRd1lfU6fhGZ6+Z/K WJY5kTSj0ywp9CpYe00dunloEgFFBjLCmYvO/C3iElScl9MwTlLUU59CFvMhkaRX B2wz23qD9fVu5XsU6nn52FpH3ORsYMDFiqOD4qqK5zkMJHJtB+SPsrVsFSDn7UnY 7xiDdI3cVFMqwdugMdlda8BSAuYL3CeKJk4F44ScNwXr8CP0m/G/NNNaVznYYsDd K9s8cCAqbWi+J78/Hy4CnwyrxmWyh3vm5c1QFaKFgoQ/6G+2FazT3xRoIeuoKqKL uokFSN4MeUul+l+Ncz2gc3bsb7F2N5q8a84+RYnb1yKqrrLo//9WFM5SZMHb8pA6 mYleWYZdNb76o0e86zEWwXgb9QlojbWT4KP7tEI3cMXOlKlvnOb86SpTcxxffAiP L4qOZw++yMex31PdL1jsO+R7ek3YeiLVgq/teMP7HYlLgxW4hN5m8AklTJC+mKGF qIflwOm2Pp5YgfLTbrMOz9+uHqRup+wxNQws3r7UYGrFd0ysYEeNkM9zT8sruSQm BxCznzjJsZmaUr7P9Ba/Hp2UOJxBlQV+1Bg6ILzK63+feUK8uqGLa66BoAYXVsSb j4Mh8Sp0Jwu4tdldrv8l =rSPd -----END PGP SIGNATURE----- --Sig_/F_Y0qVdHqBjTJ61MMYUYrrd--