From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cyril Hrubis Date: Fri, 11 May 2018 13:48:40 +0200 Subject: [LTP] [PATCH] [RFC] syscalls/perf_event_open02: Fix failures In-Reply-To: <20180503084931.GE29568@rei> References: <20180424124957.15634-1-chrubis@suse.cz> <20180503084931.GE29568@rei> Message-ID: <20180511114840.GB17721@rei> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it Hi! > > The testcase was failing randomly, it could be reproduced easily when > > the machine is under load. To reproduce the issue just run a few > > dd if=/dev/zero of=/dev/null to saturate your CPUs. > > > > It has been sugessted that the reason for the failure are rounding > > errors caused by a frequent preemption. I haven't got a definitive > > answer from kernel devs for this but it's true that changing the process > > pritority to realtime SCHED_FIFO for the measurement does fix the issue. > > > > So we either delete the test or apply this patch. > > Any comments for this patch? > > I would like to have this sorted out before the release... Since nobody commented I will apply this next week, if you are againts this patch, or want to ack it, speak up now :-). -- Cyril Hrubis chrubis@suse.cz