From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27960 invoked by alias); 6 Nov 2014 14:56:33 -0000 Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org Received: (qmail 27912 invoked by uid 89); 6 Nov 2014 14:56:32 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.5 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail7.hitachi.co.jp Received: from mail7.hitachi.co.jp (HELO mail7.hitachi.co.jp) (133.145.228.42) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 06 Nov 2014 14:56:30 +0000 Received: from mlsv3.hitachi.co.jp (unknown [133.144.234.166]) by mail7.hitachi.co.jp (Postfix) with ESMTP id E520337AC4; Thu, 6 Nov 2014 23:56:28 +0900 (JST) Received: from mfilter03.hitachi.co.jp by mlsv3.hitachi.co.jp (8.13.1/8.13.1) id sA6EuSdB031607; Thu, 6 Nov 2014 23:56:28 +0900 Received: from vshuts02.hitachi.co.jp (vshuts02.hitachi.co.jp [10.201.6.84]) by mfilter03.hitachi.co.jp (Switch-3.3.4/Switch-3.3.4) with ESMTP id sA6EuRiU026582; Thu, 6 Nov 2014 23:56:28 +0900 Received: from gxml20a.ad.clb.hitachi.co.jp (unknown [158.213.157.160]) by vshuts02.hitachi.co.jp (Postfix) with ESMTP id 0ACF1490041; Thu, 6 Nov 2014 23:56:27 +0900 (JST) Received: from [10.198.219.30] by gxml20a.ad.clb.hitachi.co.jp (Switch-3.1.10/Switch-3.1.9) id 6A6E2KQ1P00003054; Thu, 06 Nov 2014 23:56:26 +0900 Message-ID: <545B8C16.4010400@hitachi.com> Date: Thu, 06 Nov 2014 14:56:00 -0000 From: Masami Hiramatsu User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Hemant Kumar Cc: Namhyung Kim , linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com, peterz@infradead.org, oleg@redhat.com, hegdevasant@linux.vnet.ibm.com, mingo@redhat.com, anton@redhat.com, systemtap@sourceware.org, aravinda@linux.vnet.ibm.com, penberg@iki.fi, Arnaldo Carvalho de Melo Subject: Re: Re: [PATCH v4 5/5] perf/sdt: Add support to perf record to trace SDT events References: <20141102105006.21708.28734.stgit@hemant-fedora> <20141102105557.21708.19032.stgit@hemant-fedora> <87lhnr5sbl.fsf@sejong.aot.lge.com> <54588905.7040002@linux.vnet.ibm.com> <5458CD15.4010101@hitachi.com> <874muew2hk.fsf@sejong.aot.lge.com> <5459E865.6050207@hitachi.com> <545B1DDE.9000202@linux.vnet.ibm.com> In-Reply-To: <545B1DDE.9000202@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2014-q4/txt/msg00113.txt.bz2 (2014/11/06 16:06), Hemant Kumar wrote: > So, what should be our way forward here in case of SDT patchset wrt > event_cache patchset? Shall we wait for event_cache patchset to be > merged and then redesign the sdt_cache patchset according to new > event_cache? > Or, we can go ahead with the current sdt patchset (implementing the > latest review comments) and we can change the sdt_cache according to the > new event_cache design as and when required? > > What do you think? Good question :) In my opinion, we'd better consolidate sdt_cache to new cache subcommand at first, since it is a user-visible change. If we consolidate it after introducing sdt-cache, users will see that option is also banished. And also, the cache-format may be a problem, since that involves a backward compatibility issue. For now, I'm considering Namhyung's idea of merging SDT and probe caches. If we can use SDT as a kind of probe cache, why do we need to have both SDT cache and probe cache? SDT cache is currently have its own format, but it also could be written as a probe format, as below. In ~/.debug/probe/bu/ild-id: %: _text+ This lucks a semaphore location, but who cares? Anyway we can't change the semaphore. We already have reader of this format and also this can have arguments if you get it from sdt.note. :) Moreover, we can share the cache file with perf-probe! :) Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com