From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755325Ab3K0Oem (ORCPT ); Wed, 27 Nov 2013 09:34:42 -0500 Received: from mail-bk0-f54.google.com ([209.85.214.54]:47129 "EHLO mail-bk0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751169Ab3K0Oek (ORCPT ); Wed, 27 Nov 2013 09:34:40 -0500 Date: Wed, 27 Nov 2013 15:34:35 +0100 From: Ingo Molnar To: Peter Zijlstra Cc: Steven Rostedt , Juri Lelli , tglx@linutronix.de, mingo@redhat.com, oleg@redhat.com, fweisbec@gmail.com, darren@dvhart.com, johan.eker@ericsson.com, p.faure@akatech.ch, linux-kernel@vger.kernel.org, claudio@evidence.eu.com, michael@amarulasolutions.com, fchecconi@gmail.com, tommaso.cucinotta@sssup.it, nicola.manica@disi.unitn.it, luca.abeni@unitn.it, dhaval.giani@gmail.com, hgu1972@gmail.com, paulmck@linux.vnet.ibm.com, raistlin@linux.it, insop.song@gmail.com, liming.wang@windriver.com, jkacur@redhat.com, harald.gustafsson@ericsson.com, vincent.guittot@linaro.org, bruce.ashfield@windriver.com Subject: Re: [PATCH 08/14] sched: add latency tracing for -deadline tasks. Message-ID: <20131127143435.GD25043@gmail.com> References: <1383831828-15501-1-git-send-email-juri.lelli@gmail.com> <1383831828-15501-9-git-send-email-juri.lelli@gmail.com> <20131120163318.10253e43@gandalf.local.home> <5295F711.5010708@gmail.com> <20131127091647.4e16ce53@gandalf.local.home> <20131127142649.GC13532@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131127142649.GC13532@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra wrote: > On Wed, Nov 27, 2013 at 09:16:47AM -0500, Steven Rostedt wrote: > > On Wed, 27 Nov 2013 14:43:45 +0100 > > Juri Lelli wrote: > > diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c > > > index f76f8d6..ad94604 100644 > > > --- a/kernel/trace/trace_selftest.c > > > +++ b/kernel/trace/trace_selftest.c > > > @@ -1023,16 +1023,16 @@ trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr) > > > static int trace_wakeup_test_thread(void *data) > > > { > > > /* Make this a -deadline thread */ > > > - struct sched_param2 paramx = { > > > + static const struct sched_param2 param = { > > > .sched_priority = 0, > > > + .sched_flags = 0, > > > .sched_runtime = 100000ULL, > > > .sched_deadline = 10000000ULL, > > > .sched_period = 10000000ULL > > > - .sched_flags = 0 > > > > Assigning structures like this, you don't need to set the zero fields. > > all fields not explicitly stated, are set to zero. > > Only because its static. Otherwise unnamed members have indeterminate > value after initialization. I think for 'struct' C will initialize them to zero, even if they are not mentioned and even if they are on the stack. It will only be indeterminate when it's not initialized at all. Thanks, Ingo