From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Perf trace event parse errors for KVM events Date: Tue, 01 Jun 2010 15:39:01 +0300 Message-ID: <4C04FF65.8020408@redhat.com> References: <20100526123443.GB8905@stefan-thinkpad.transitives.com> <1275083157.22648.593.camel@gandalf.stny.rr.com> <4C00FF9B.9000107@redhat.com> <1275139177.22648.610.camel@gandalf.stny.rr.com> <4C021D7E.1060705@redhat.com> <1275228182.15884.1.camel@gandalf.stny.rr.com> <4C027131.2010309@redhat.com> <1275233656.15884.4.camel@gandalf.stny.rr.com> <4C04C739.8050607@redhat.com> <1275393544.15884.19.camel@gandalf.stny.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Stefan Hajnoczi , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Frederic Weisbecker , Marcelo Tosatti , Peter Zijlstra , Stefan Hajnoczi , Johannes Berg , Darren Hart To: rostedt@goodmis.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:27217 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753328Ab0FAMjO (ORCPT ); Tue, 1 Jun 2010 08:39:14 -0400 In-Reply-To: <1275393544.15884.19.camel@gandalf.stny.rr.com> Sender: kvm-owner@vger.kernel.org List-ID: On 06/01/2010 02:59 PM, Steven Rostedt wrote: > >> One concern is performance. Traces tend to be long, and running python >> code on each line will be slow. >> >> If trace-cmd integrates a pager and a search mechanism that looks at the >> binary data instead of the text, we could format only the lines that are >> displayed. But that is going to be a lot of work and I don't think it's >> worth the effort. >> >> > Every event gets its own ID. The plugin registers a callback to that ID. > When the ID is hit, the plugin is executed on that event to display its > binary format. > > This is done after the data has been saved in binary format to a file. > It may slow down the executing of reading a data file, but it does not > affect the running of the trace one bit. > I meant that viewing would be slowed down. It's an important part of using ftrace! How long does the Python formatter take to process 100k or 1M events? -- error compiling committee.c: too many arguments to function