Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753995AbbGUKmi (ORCPT ); Tue, 21 Jul 2015 06:42:38 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:45233 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752670AbbGUKmh (ORCPT ); Tue, 21 Jul 2015 06:42:37 -0400 Message-ID: <55AE2216.4080109@hitachi.com> Date: Tue, 21 Jul 2015 19:42:30 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 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: [RFC PATCH perf/core v2 15/16] perf buildid-cache: Scan and import user SDT events to probe cache References: <20150715091352.8915.87480.stgit@localhost.localdomain> <20150715091537.8915.63535.stgit@localhost.localdomain> <20150719104612.GB25163@danjae.kornet> <55AC68B2.6080905@hitachi.com> <20150720155207.GB9265@danjae.kornet> In-Reply-To: <20150720155207.GB9265@danjae.kornet> 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: 2454 Lines: 68 On 2015/07/21 0:52, Namhyung Kim wrote: > On Mon, Jul 20, 2015 at 12:19:14PM +0900, Masami Hiramatsu wrote: >> On 2015/07/19 19:46, Namhyung Kim wrote: >>> On Wed, Jul 15, 2015 at 06:15:37PM +0900, Masami Hiramatsu wrote: >>>> perf buildid-cache --add scans given binary and add >>>> the SDT events to probe cache. It is possible to use the cached >>>> SDT events as other cached events (perf probe :=). >>> >>> That means lookup the cached SDT events only using event name, right? >> >> Right, >> >>> What if same event names are used by more than one providers? >> >> That's a good discussion point :) >> >> What I'm thinking is that the real SDT is always prior to other >> cached events. (currently not implemented yet) >> - if someone gives a same event name, it overwrites previous one. >> - if someone gives an event name same as existing SDT, it is not >> cached (or rejected) >> - if SDT scanned after cached same name events, SDT always overwrites >> the entry. > > I'm thinking about allowing same name for different events. IMHO it's > possible to have same SDT names for some reason - i.e. having multiple > versions of same program, similar (but different) binaries have same > event names, or even in a single bianry it might have same event names > but different provider names. > > In that case, I think perf probe (or record) simply can do the job for > every matching events. Hmm, right. If we support the 3-level event name as you said, that can make things much simpler. We can use "probe_<12chars-buildid>" for the toplevel dirname, and "provider/name" for lower 2 levels. Or, if we can use ./ for the group name (this requres kernel change) it is more easier to support SDTs. Thank you, > >> >> So, the all SDT events will be treated as fixed events. >> >> Note that this will be happen if we agree SDT and probe share the >> same namespace :) > > Right. > > Thanks, > Namhyung > > -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group 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/