From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Perf trace event parse errors for KVM events Date: Sun, 06 Jun 2010 11:08:31 +0300 Message-ID: <4C0B577F.9050506@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> <4C04FF65.8020408@redhat.com> <1275602225.15884.47.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]:55528 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752260Ab0FFIIq (ORCPT ); Sun, 6 Jun 2010 04:08:46 -0400 In-Reply-To: <1275602225.15884.47.camel@gandalf.stny.rr.com> Sender: kvm-owner@vger.kernel.org List-ID: On 06/04/2010 12:57 AM, Steven Rostedt wrote: > On Tue, 2010-06-01 at 15:39 +0300, Avi Kivity wrote: > >> On 06/01/2010 02:59 PM, Steven Rostedt wrote: >> > >> 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? >> >> > I finally got around to testing this. > > I ran a trace on lock_acquire, and traced 1,253,296 events. > > I then created a python plugin to analyze the trace: > > ---- > def lock_acquire(trace_seq, event): > t = '' > r = '' > if int(event['flags'])& 1: > t = 'try' > if int(event['flags'])& 2: > r = 'read' > trace_seq.puts('t %x %s%s%s' % ( > event['lockdep_addr'], t, r, > event['name'])) > > def register(pevent): > pevent.register_event_handler("lock", "lock_acquire", lock_acquire) > ---- > > Disclaimer, I'm not a python expert, and I'm sure the above python code > sucks. > I think Python more or less guarantees your code will suck no matter what you do. > [root@ixf9 trace-cmd.git]# time ./trace-cmd report -N>/dev/null 2>&1 > > real 0m4.653s > user 0m4.234s > sys 0m0.419s > > * -N keeps trace-cmd from loading any plugins. > > > [root@ixf9 trace-cmd.git]# time PYTHONPATH=`pwd` ./trace-cmd report>/dev/null 2>&1 > > real 0m53.916s > user 0m53.047s > sys 0m0.859s > > > Yes, running a python interpreter is a bit more expensive. It took 4 > seconds to read the million events with plain C, but 53 seconds to read > it in python. > > That said... This would only affect you if you were writing this to a > file. I doubt that you would notice this if you were scanning the trace > with less. > I'm more worried about searching with less. But a minute for a million events isn't that bad. > Also, I kicked this off in kernelshark, and it made no difference that I > can see. This is because kernelshark only evaluates the viewable area of > the screen. > Neat. Can it also search? Where can I find it? -- error compiling committee.c: too many arguments to function