Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752835AbaKJMbz (ORCPT ); Mon, 10 Nov 2014 07:31:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42841 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752577AbaKJMby (ORCPT ); Mon, 10 Nov 2014 07:31:54 -0500 Date: Mon, 10 Nov 2014 10:31:31 -0200 From: Arnaldo Carvalho de Melo To: Hagen Paul Pfeifer Cc: Masami Hiramatsu , Hemant Kumar , 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, "yrl.pp-manager.tt@hitachi.com" Subject: Re: [RFC] perf-cache command interface design Message-ID: <20141110123131.GD4468@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: 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 Mon, Nov 10, 2014 at 01:05:45PM +0100, Hagen Paul Pfeifer escreveu: > On 7 November 2014 09:21, Masami Hiramatsu > wrote: > > > 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 > > and that is linked to ~/.debug/.probes/.buildid/bu/ildid > > # To avoid conflict with files under /probes/*, I picked up .probes/. > > A little bit late: but why ~/.debug? Why not $XDG_CACHE_HOME/perf/ as Why "perf"? > the root for all perf related files? debug is not unique nor is it sufficient Probably should be some other name then, but ~/.debug/ is there since the build-id cache was introduced, guess this is why it is being kept so far in Masami's proposal. > to meet file hierarchy: man file-hierarchy(8) Humm, It starts in $HOME/.debug/ because this is not supposed to be a system wide cache, a developer can, for instance: 1. perf record myapp 2. edit myapp.c 3. rebuild it 4. perf record myapp 5. perf diff And it will show the difference from the previous version, for which it stored a copy of its binary on its private, keyed by build-id, cache. So this is not merely a place where we will read stuff from. If somebody decides to have it in a place accessible by multiple users on the same system, then, yes, some more suitable place outside its $HOME is needed, and then tooling should look there as well as on the places it already looks for such files, i.e. $HOME/.debug/, /usr/lib/debug (where foo-debuginfo packages store stuff, also keyed by build-id), /lib/modules/$KVR/, etc. - 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/