Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751732Ab3JZLQm (ORCPT ); Sat, 26 Oct 2013 07:16:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62129 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751551Ab3JZLQl (ORCPT ); Sat, 26 Oct 2013 07:16:41 -0400 To: Pekka Enberg Cc: Hemant Kumar , 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 Subject: Re: [PATCH v4 2/3] Support for perf to probe into SDT markers: References: <20131023044511.1886.82571.stgit@hemant-fedora> <20131023050502.1886.15779.stgit@hemant-fedora> From: fche@redhat.com (Frank Ch. Eigler) Date: Sat, 26 Oct 2013 07:16:05 -0400 In-Reply-To: (Pekka Enberg's message of "Fri, 25 Oct 2013 14:38:17 +0200") Message-ID: User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1033 Lines: 27 Pekka Enberg writes: > Is there a technical reason why 'perf list' could not show all the > available SDT markers on a system and that the 'mark to event' > mapping cannot happen automatically? [...] A quick experiment with: find `echo $PATH | tr : ' '` -type f -perm -555 | xargs readelf -n 2>/dev/null | grep STAP 2>/dev/null suggests reasonable performance for my F19 workstation (a second or two over ~6000 executables), once all the ELF content is in the block cache. According to a stap eventcount.stp run, that required about 50000 syscall.read events. Note that a $PATH search excludes shared libraries, which can also carry markers. Adding /usr/lib* in more than doubles the work, then there's /usr/libexec etc. - FChE -- 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/