From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932208AbbC3VPS (ORCPT ); Mon, 30 Mar 2015 17:15:18 -0400 Received: from smtprelay0042.hostedemail.com ([216.40.44.42]:38975 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932154AbbC3VPP (ORCPT ); Mon, 30 Mar 2015 17:15:15 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1540:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:2693:3138:3139:3140:3141:3142:3352:3622:3865:3866:3867:3868:3870:3871:3872:3874:5007:6261:7875:7903:8660:10004:10400:10848:10946:10967:11232:11658:11914:12517:12519:12740:13069:13148:13180:13184:13229:13230:13311:13357:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: thing22_1062083302513 X-Filterd-Recvd-Size: 1862 Date: Mon, 30 Mar 2015 17:15:11 -0400 From: Steven Rostedt To: Namhyung Kim Cc: Shuah Khan , LKML , Michael Ellerman , Dave Jones , Luis Henriques Subject: Re: [PATCH] ftracetest: Do not use usleep Message-ID: <20150330171511.5722493b@gandalf.local.home> In-Reply-To: <1427329943-16896-1-git-send-email-namhyung@kernel.org> References: <1427329943-16896-1-git-send-email-namhyung@kernel.org> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 26 Mar 2015 09:32:23 +0900 Namhyung Kim wrote: > The usleep is only provided on distros from Redhat so running ftracetest > on other distro resulted in failures due to the missing usleep. > > The reason of using [u]sleep in the test was to generate (scheduler) > events. But as we use 'cat trace | grep | wc -l' to read the events, > the command themselves already generate some events before reading the > trace file so no need to call [u]sleep explicitly. Note, opening "trace" via cat stops tracing. There is a possible race where the cat will not produce events. My worry is that if the shell implements its own "cat" command, it may not fork, and open the trace file. Which would not have any events in it, and opening it will disable the rest of the command from having events. What about using: ping localhost -c 1 ? -- Steve