Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752668AbaKGOib (ORCPT ); Fri, 7 Nov 2014 09:38:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53307 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752392AbaKGOia (ORCPT ); Fri, 7 Nov 2014 09:38:30 -0500 Date: Fri, 7 Nov 2014 12:38:04 -0200 From: Arnaldo Carvalho de Melo To: Masami Hiramatsu Cc: Hemant Kumar , Adrian Hunter , Mark Wielaard , David Ahern , Jiri Olsa , 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, systemtap@sourceware.org, aravinda@linux.vnet.ibm.com, penberg@iki.fi, brendan.d.gregg@gmail.com, acme@kernel.org, "yrl.pp-manager.tt@hitachi.com" Subject: Re: [RFC] perf-cache command interface design Message-ID: <20141107143804.GA2137@redhat.com> 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> <545C80F4.4020905@hitachi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <545C80F4.4020905@hitachi.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Nov 07, 2014 at 05:21:08PM +0900, Masami Hiramatsu escreveu: > Hello, > > Here, I've tried to describe my idea of perf-cache subcommand interface. > It is just a design review, not implemented yet :) > Please give me your comments/ideas! > > Command-line Synopsis > ===================== > > Current "perf buildid-cache [options]" are directly mapped to > "perf cache --buildid [options]". > > And adding --sdt for managing SDT caches as below. Can't we avoid having to specify the content? I.e. the tool can surely be smart enough to figure that out, no? We should, as much as possible, to make things more compact yet unambiguous, IMHO. > Add or update SDT events in > perf cache --sdt --add|--update Can automagically figure this out, so, it would become just: Add or update events in perf cache --add/--update > Remove all SDT events for > perf cache --sdt --remove Ditto. > List all SDT events > perf cache --sdt --list That is ok, since the cache can hold different types of contents, but: perf cache --list should show everything, with some marking showing the content type. > And --probes for managing probe-caches as below. > > Add new probe-cache entries for kernel, or . > perf cache --probe [--exec |--module ] --add No need to specify --probe > Delete existing probe-cache entries for kernel, or/and . > perf cache --probe --del [:][@][#] Ditto > Or remove all entires for given FILES > perf cache --probe --remove Ok > List the probe caches(including SDT) for kernel, , or/and . > perf cache --probe --list [@][#] Can figure out the kind by the initial character, so no need to specify --probe > Query the probe definitions. > perf cache --probe --query [:][@][#] Ditto > Note that --probes also can be used for managing SDT events, which has % prefix > e.g. > Add all SDT events for > perf cache --probe --exec --add '%*:*' See? --probe is smart enough to deal with SDT and probe caches, it can disambiguate by looking at the first char. > Remove some SDT events for > perf cache --probe --del '%some:events@' No need for --probe > Or remove all SDT events for > perf cache --probe --del '%*:*#' Ditto > > File Format > =========== > All the cache files are placed under ~/.debug/ by default. > The paths of buildid cache of binary/symbols are not changed. > > The SDT/probe caches are placed under the ~/.debug/.probes/path/to/bin/bu/ildid Here I think we could group everything related to a /path/to/bin into: ~/.debug/path/to/bin/bu/ild/ With one file per content type: ~/.debug/path/to/bin/bu/ild/elf ~/.debug/path/to/bin/bu/ild/probe That leaves room for us to add more file formats (CTF anyone? The Dtrace one, Compact C Type Information, I mean). So that if we wanted to pick everything related to a pathname we could do: tar cf gcc.debug.tar ~/.debug/usr/bin/gcc/ If we instead wanted to pick all files to a specific gcc build id, we would do: tar cf gcc.debug.tar ~/.debug/usr/bin/gcc/bu/ild/ > and that is linked to ~/.debug/.probes/.buildid/bu/ildid Since this would break compatibility with the existing cache format, we could as well allow collecting everything related to a build id, by making the link be also in this fashion: tar cf bu.ildid.tar ~/.debug/.build-id/bu/ildid/ Because we would have: ~/.debug/.build-id/bu/ildid/elf -> ~/.debug/usr/bin/gcc/bu/ild/elf ~/.debug/.build-id/bu/ildid/probe -> ~/.debug/usr/bin/gcc/bu/ild/probe And also links to the files that have no pathnames: ~/.debug/.build-id/bu/ildid/vdso -> ~/.debug/[vdso]/bu/ild ~/.debug/.build-id/bu/ildid/kallsyms -> ~/.debug/[kernel.kallsyms]/bu/ild ~/.debug/.build-id/bu/ildid/kcore -> ~/.debug/[kcore]/bu/ild > # To avoid conflict with files under /probes/*, I picked up .probes/. > > This SDT/probe caches contain probe-definitions as following format. > ---- > #buildid:BUILDID > #path:PATH > p:%PROVIDER/EVENT PATH:OFFSET [ARGS] > p:PROBE/EVENT _text+OFFSET [ARGS] > ---- > > Normal probes and SDT cache entries can be mixed in a cache file, we'll > load all the entries and filter by % prefixes. - Arnaldo -- 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/