From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-trace-devel-owner@vger.kernel.org Received: from mail.kernel.org ([198.145.29.99]:33620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752279AbdLRPmB (ORCPT ); Mon, 18 Dec 2017 10:42:01 -0500 Date: Mon, 18 Dec 2017 10:41:58 -0500 From: Steven Rostedt To: David Hildenbrand Cc: Linux Kernel Mailing List , Linux Trace Devel Subject: Re: [PATCH v1] trace-cmd: introduce --initital-delay for record command Message-ID: <20171218104158.22519a7e@gandalf.local.home> In-Reply-To: <20171218112412.11898-1-david@redhat.com> References: <20171218112412.11898-1-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-trace-devel-owner@vger.kernel.org List-ID: On Mon, 18 Dec 2017 12:24:12 +0100 David Hildenbrand wrote: > If recording a big number of events to a big buffer, one might want to > minimize the trace-cmd activity for a certain period in time. > Especially, don't see any trace-cmd activity for some time. If there are > a lot of events, the loop might actually never sleep, resulting in the > "-s" option never becomming active. > > E.g. I am using scheduler events to trace thread activity per CPU. Esp. > sched:sched_wakeup and sched:sched_stat_runtime. Even when setting the > sleep time to something huge like 30 seconds, I can see constant activity > from the trace-cmd tasks. Thanks for reporting this. Honestly, I believe this is fixing a symptom of a real problem. I'd like to investigate why trace-cmd is running with a sleep time of 30 seconds. I think that should be fixed. -- Steve