Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753708AbbBKPKz (ORCPT ); Wed, 11 Feb 2015 10:10:55 -0500 Received: from mail.kernel.org ([198.145.29.136]:44787 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753078AbbBKPKx (ORCPT ); Wed, 11 Feb 2015 10:10:53 -0500 Date: Wed, 11 Feb 2015 11:57:42 -0300 From: Arnaldo Carvalho de Melo To: Masami Hiramatsu Cc: Peter Zijlstra , Adrian Hunter , linux-kernel@vger.kernel.org, Ingo Molnar , Paul Mackerras , Jiri Olsa , Namhyung Kim , Borislav Petkov , Hemant Kumar Subject: Re: [perf/core PATCH v2 3/4] perf buildid-cache: Add new buildid cache if update target is not cached Message-ID: <20150211145742.GI24251@kernel.org> References: <20150210091849.19264.63698.stgit@localhost.localdomain> <20150210091855.19264.32910.stgit@localhost.localdomain> <20150211144928.GH24251@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150211144928.GH24251@kernel.org> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2368 Lines: 55 Em Wed, Feb 11, 2015 at 11:49:28AM -0300, Arnaldo Carvalho de Melo escreveu: > Em Tue, Feb 10, 2015 at 06:18:56PM +0900, Masami Hiramatsu escreveu: > > Add new buildid cache if the update target file is not cached. > > This can happen when an old binary is replaced by new one > > after caching the old one. In this case, user sees his operation > > just failed. But it does not look straight, since user just > > pass the binary "path", not "build-id". > > > > ---- > > # ./perf buildid-cache --add ./perf > > (update ./perf to new binary) > > # ./perf buildid-cache --update ./perf > > ./perf wasn't in the cache > > Humm, without re-reading the original motivation for the '--update' > operation I would think it was about finding all build-ids in the cache > that are for a binary with that path, remove them and insert this new > one, no? > > Checking... commit eeb49845425375481f14c0e5721f88242642e88e Author: Namhyung Kim Date: Thu Feb 7 18:02:11 2013 +0900 perf buildid-cache: Add --update option When adding vmlinux file to build-id cache, it'd be fail since kallsyms dso with a same build-id was already added by perf record. So one needs to remove the kallsyms first to add vmlinux into the cache. Add --update option for doing it at once. ---------------------------------------------------------------------------------- So this was really a 'remove the file that is pointed by this build-id' and replace with this new file, i.e. there is both a vmlinux _and_ a kallsyms file for the same build-id. When wanting to use one or the other and existing a link in the cache, one uses this --update thing. That is ok for cases where there are multiple symtabs in the cache for a given build-id, but as you mention above, it is confusing for updating by _pathname_. What a 'update' by pathname would mean? I guess it would be to remove 'old', i.e. 'not up-to-date' stuff, i.e. older build-ids that that pathname had in the past, and leave just this new stuff. The way you did it make '--update path' be equivalent to '--add path'. - 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/