Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753244Ab3JYMiT (ORCPT ); Fri, 25 Oct 2013 08:38:19 -0400 Received: from mail-wg0-f46.google.com ([74.125.82.46]:44081 "EHLO mail-wg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751379Ab3JYMiS (ORCPT ); Fri, 25 Oct 2013 08:38:18 -0400 MIME-Version: 1.0 In-Reply-To: <20131023050502.1886.15779.stgit@hemant-fedora> References: <20131023044511.1886.82571.stgit@hemant-fedora> <20131023050502.1886.15779.stgit@hemant-fedora> Date: Fri, 25 Oct 2013 14:38:17 +0200 X-Google-Sender-Auth: NihYnsYmSlaZI65US06hWPZ8Y4M Message-ID: Subject: Re: [PATCH v4 2/3] Support for perf to probe into SDT markers: From: Pekka Enberg To: Hemant Kumar Cc: LKML , Srikar Dronamraju , Peter Zijlstra , Oleg Nesterov , hegdevasant@linux.vnet.ibm.com, Ingo Molnar , anton@redhat.com, systemtap@sourceware.org, Namhyung Kim , Masami Hiramatsu , aravinda@linux.vnet.ibm.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1580 Lines: 47 Hello Hemant, On Wed, Oct 23, 2013 at 7:05 AM, Hemant Kumar wrote: > This allows perf to probe into the sdt markers/notes present in > the libraries and executables. We try to find the associated location > and handle prelinking (since, stapsdt notes section is not allocated > during runtime). Prelinking is handled with the help of base > section which is allocated during runtime. This address can be compared > with the address retrieved from the notes' description. If its different, > we can take this difference and then add to the note's location. > > We can use existing '-a/--add' option to add events for sdt markers. > Also, we can add multiple events at once using the same '-a' option. > > Usage: > perf probe -x /lib64/libc.so.6 -a 'my_event=%libc:setjmp' > > Output: > Added new event: > libc:my_event (on 0x35981) > > You can now use it in all perf tools, such as: > > perf record -e libc:my_event -aR sleep 1 Is there a technical reason why 'perf list' could not show all the available SDT markers on a system and that the 'market to event' mapping cannot happen automatically? So instead of doing all the command line magic above I'd do: perf list libc:setjmp [SDT marker] and I could just do perf record -e libc:setjmp -AR sleep 1 ? Pekka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/