Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754333AbbHSPPf (ORCPT ); Wed, 19 Aug 2015 11:15:35 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:55782 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753930AbbHSPPe (ORCPT ); Wed, 19 Aug 2015 11:15:34 -0400 From: =?utf-8?B?5bmz5p2+6ZuF5bezIC8gSElSQU1BVFXvvIxNQVNBTUk=?= To: "'Namhyung Kim'" CC: Arnaldo Carvalho de Melo , Peter Zijlstra , "linux-kernel@vger.kernel.org" , Adrian Hunter , "Ingo Molnar" , Paul Mackerras , Jiri Olsa , Borislav Petkov , Hemant Kumar Subject: RE: Re: [RFC PATCH perf/core v3 00/17] perf-probe --cache and SDT support Thread-Topic: [!!]Re: [RFC PATCH perf/core v3 00/17] perf-probe --cache and SDT support Thread-Index: AQHQ11Au44mrx4ywwUCe68EujkZymJ4SbQcAgAEA+JA= Date: Wed, 19 Aug 2015 15:15:30 +0000 Message-ID: <50399556C9727B4D88A595C8584AAB37524CA832@GSjpTKYDCembx32.service.hitachi.net> References: <20150815114252.13642.62690.stgit@localhost.localdomain> <20150819083012.GA16725@sejong> In-Reply-To: <20150819083012.GA16725@sejong> Accept-Language: ja-JP, en-US Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.198.219.54] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id t7JFFdWl022045 Content-Length: 1246 Lines: 32 Hi Namhyung, > From: Namhyung Kim [mailto:namhyung@gmail.com] On Behalf Of Namhyung Kim > > - (ftrace) Support multiple SDTs on single event. > > > > Since multiple same SDTs are defined in a single binary (e.g. libc:setjump > > has 3 different entries on libc-2.17.so), we need the last feature on > > ftrace, so that a single uprobe event can occur several different > > probe points. > > Do you want to have multiple events of same name in the kernel? Or > to make perf handle those same names with different kernel events? Good point, I meant the former. But the latter is also possible. Here is my idea; Suppose to define an event "foo" at "bar" function + 10byte offset with 2 arguments as below: # echo p:foo bar+10 arg1=%ax arg2=%dx > kprobe_events To add a probe point on the same event, use "+p" or "+r" instead of "p" or "r" and we can also change the assignment for each argument. # echo +p:foo bar+20 arg1=%cx arg2=0 >> kprobe_events Also, I guess we'll need to support a fixed value assignment because sometimes local valiables are optimized out. Thank you, ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?