Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757906Ab3J2DTm (ORCPT ); Mon, 28 Oct 2013 23:19:42 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:51717 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756666Ab3J2DTl (ORCPT ); Mon, 28 Oct 2013 23:19:41 -0400 Message-ID: <526F2949.5000208@hitachi.com> Date: Tue, 29 Oct 2013 12:19:37 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Pekka Enberg Cc: Srikar Dronamraju , Hemant Kumar , LKML , Peter Zijlstra , Oleg Nesterov , hegdevasant@linux.vnet.ibm.com, Ingo Molnar , anton@redhat.com, systemtap@sourceware.org, Namhyung Kim , aravinda@linux.vnet.ibm.com Subject: Re: 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> <526E4940.8000608@hitachi.com> <526E5BA5.7050103@iki.fi> <20131028141152.GA1040@linux.vnet.ibm.com> <526E72EC.9060400@iki.fi> <20131028173152.GB1040@linux.vnet.ibm.com> <526EA366.4020204@iki.fi> In-Reply-To: <526EA366.4020204@iki.fi> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2019 Lines: 57 (2013/10/29 2:48), Pekka Enberg wrote: > On 10/28/13 7:31 PM, Srikar Dronamraju wrote: >>>> But what if a system has both 32 bit libc and 64 bit libc? >>>> Wont we could end up with 2 libc:setjmp? >>>> Should we give some more intelligence into perf to choose the 64 bit >>>> libc over 32 bit one? >>> You can just trace both of them by default, no? >>> >> There has to be a one to one association with the event name and its >> mapping. Every event name will finally map to a unique inode and an >> offset. >> >> One option would be for perf to look at these markers and have a >> different event name for similar markers in different executables. > > I think we are talking past each other here. > > Yes, I understand that you need an fully qualified name > for a SDT marker but there's absolutely no reason to force > feed that to the user of 'perf trace'. > > For the 32-bit and 64-bit libc case, why cannot 'perf list' > by default print out something like: > > $ perf list > > libc:setjmp [SDT marker group] > > and provide a '--fully-qualified' command line option that: > > $ perf list --fully-qualified > > libc:setjmp => libc32:setjmp, libc64:setjmp [SDT marker group] > libc32:setjmp => libc:setjmp@/lib/libc.so.6 [SDT marker] > libc64:setjmp => libc:setjmp@/lib64/libc.so.6 [SDT marker] > > and then teach 'perf trace' to deal with SDT marker groups > where you trace two events, not one? Ah, that's a good idea. :) And it also is needed for another probe event because sometimes inlined functions have multiple instances. I'd like to fold them as one event group. Thank you! -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- 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/