Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755350Ab3J1Ikn (ORCPT ); Mon, 28 Oct 2013 04:40:43 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:53145 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750998Ab3J1Ikl (ORCPT ); Mon, 28 Oct 2013 04:40:41 -0400 X-Sasl-enc: irXBiIskrwcE5Odee7XJEOaRKHbyu+1JlAI/3Vk3VoY9 1382949640 Message-ID: <526E2304.1000407@iki.fi> Date: Mon, 28 Oct 2013 10:40:36 +0200 From: Pekka Enberg User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: "Frank Ch. Eigler" , 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> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1262 Lines: 31 On 10/26/2013 02:16 PM, Frank Ch. Eigler wrote: > 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. Thanks for providing numbers to the discussion. AFAICT, we might even be able to just scan everything for 'perf list' by default. 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/