Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756313Ab3J1Mmf (ORCPT ); Mon, 28 Oct 2013 08:42:35 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:48262 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756101Ab3J1Mm0 (ORCPT ); Mon, 28 Oct 2013 08:42:26 -0400 X-Sasl-enc: 6FHEn2/SOPLYfzEJs7n8kfxXQRm2F2gv4rwd++/jBrnX 1382964136 Message-ID: <526E5BA5.7050103@iki.fi> Date: Mon, 28 Oct 2013 14:42:13 +0200 From: Pekka Enberg User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Masami Hiramatsu 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 , 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> <526E4940.8000608@hitachi.com> In-Reply-To: <526E4940.8000608@hitachi.com> Content-Type: text/plain; charset=UTF-8; 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: 1312 Lines: 34 On 10/28/13 1:23 PM, Masami Hiramatsu wrote: > By the way, what happens if multiple binaries has same SDT marker? > Yeah, perf list shows just one and ignores others. However, if we > probe one, and run binary which use the other one, user will never > see the marker. > > So, it still needs a concrete binary path to list or, we should > support a syntax which specify actual binary, as like as below. > > perf probe 'my_event=%libc:setjmp@/lib64/libc.so.6' > > And perf list may show the marker as in same syntax (for copy&paste). > > # perf list --sdt > %libc:setjmp@/lib64/libc.so.6 > ... > > Note that we need '%' to separate namespace :(, since user can define > any marker(provider) name in their binary... Sure, you need to support that sort of 'fully qualified name' for duplicate symbols but the default 'libc:setjmp' should still point to system libc. This is an example where tracing libc that's relevant to most of the users should take priority over the 'duplicate marker in obscure executable' corner case case. 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/