From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754923AbbAIPDR (ORCPT ); Fri, 9 Jan 2015 10:03:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46663 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752108AbbAIPDQ (ORCPT ); Fri, 9 Jan 2015 10:03:16 -0500 Date: Fri, 9 Jan 2015 13:03:14 -0200 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: Masami Hiramatsu , David Ahern , Namhyung Kim , linux-kernel@vger.kernel.org Subject: Re: [BUG] perf probe can't insert return kprobe Message-ID: <20150109150314.GS2517@redhat.com> References: <20150109145539.GC14750@krava.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150109145539.GC14750@krava.brq.redhat.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Jan 09, 2015 at 03:55:39PM +0100, Jiri Olsa escreveu: > hi, > I couldn't use following perf command to insert return probe: > > # perf probe -a fork_exit=do_fork%return > Added new event: > Failed to write event: Invalid argument > Error: Failed to add events. Wonder if we have any way of forcing 'perf probe' to show what it will feed the kernel, perhaps -v? > > I'm pretty sure I used this command before, so seems like > it's broken. I can still use debugfs tracing interface to > do that: > # echo 'r:do_fork_entry do_fork' > kprobe_events > > I used Arnaldo's latest perf/core and FC20 kernel: > > # uname -a > Linux krava 3.17.7-200.fc20.x86_64 #1 SMP Wed Dec 17 03:35:33 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux > # ./perf version > perf version 3.18.g6a7d78 > > > thanks, > jirka