Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752469AbcDZOmc (ORCPT ); Tue, 26 Apr 2016 10:42:32 -0400 Received: from mail.kernel.org ([198.145.29.136]:45767 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752248AbcDZOma (ORCPT ); Tue, 26 Apr 2016 10:42:30 -0400 Date: Tue, 26 Apr 2016 23:42:25 +0900 From: Masami Hiramatsu To: Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, Namhyung Kim , Peter Zijlstra , Ingo Molnar , Hemant Kumar , Ananth N Mavinakayanahalli Subject: Re: [PATCH perf/core v4 03/19] perf buildid-cache: Fall back to the old style build-id cache Message-Id: <20160426234225.204ed49b76d02442fc57ec83@kernel.org> In-Reply-To: <20160426134749.GB20998@kernel.org> References: <20160426090200.11891.43944.stgit@devbox> <20160426090233.11891.70554.stgit@devbox> <20160426134749.GB20998@kernel.org> X-Mailer: Sylpheed 3.4.3 (GTK+ 2.24.28; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4224 Lines: 123 On Tue, 26 Apr 2016 10:47:49 -0300 Arnaldo Carvalho de Melo wrote: > Em Tue, Apr 26, 2016 at 06:02:33PM +0900, Masami Hiramatsu escreveu: > > Fall back to the old style build-id cache > > (~/.debug//) if possible. > > Because there is old build-id cache under ~/.debug, perf > > has to check if the old entry is there instead of returning > > an error. Or, user have to remove ~/.debug completely. > > So, from the description this seems to address the issues I mentioned in > the previous patch. yes :) > > Probably it is a good idea not to introduce the problem in the first > place? I.e. combine this and the previous patch, so that we don't have > this bisection break? Yeah, I just try to keep original clean for review. I'll combine this with 02/19. Thanks! > > - Arnaldo > > > This patch introduces fallback code to try using old-style > > buildid caches. To update the cached entry, you just need to > > add a cache. It automatically removes old cache entry and > > make a new one in new style > > (~/.debug///[elf|vdso|kallsyms]). > > > > IOW, without this patch, "perf buildid-cache --add" always > > gets errors when adding existing binaries. > > ---- > > # perf buildid-cache -a /usr/lib64/libc-2.20.so,/usr/bin/gcc > > Couldn't add /usr/bin/gcc: Not a directory > > Couldn't add /usr/lib64/libc-2.20.so: Not a directory > > ---- > > Moreover, --update option removes only symlink, thus the > > build-id cache is corrupted. > > > > This fixes above issues. > > > > Signed-off-by: Masami Hiramatsu > > --- > > tools/perf/util/build-id.c | 17 ++++++++++++++++- > > tools/perf/util/symbol.c | 13 +++++++++---- > > 2 files changed, 25 insertions(+), 5 deletions(-) > > > > diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c > > index 46a8bcc..b035483 100644 > > --- a/tools/perf/util/build-id.c > > +++ b/tools/perf/util/build-id.c > > @@ -155,6 +155,12 @@ static char *build_id_cache__linkname(const char *sbuild_id, char *bf, > > return bf; > > } > > > > +static bool __is_regular_file(const char *pathname) > > +{ > > + struct stat sb; > > + return stat(pathname, &sb) == 0 && S_ISREG(sb.st_mode); > > +} > > + > > static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso) > > { > > return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf"); > > @@ -177,7 +183,11 @@ char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size) > > if (!linkname) > > return NULL; > > > > - ret = asnprintf(&bf, size, "%s/%s", linkname, > > + /* Check if old style build_id cache */ > > + if (__is_regular_file(linkname)) > > + ret = asnprintf(&bf, size, "%s", linkname); > > + else > > + ret = asnprintf(&bf, size, "%s/%s", linkname, > > build_id_cache__basename(is_kallsyms, is_vdso)); > > if (ret < 0 || (!alloc && size < (unsigned int)ret)) > > bf = NULL; > > @@ -445,6 +455,11 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name, > > if (!dir_name) > > goto out_free; > > > > + /* Remove old style build-id cache */ > > + if (__is_regular_file(dir_name)) > > + if (unlink(dir_name)) > > + goto out_free; > > + > > if (mkdir_p(dir_name, 0755)) > > goto out_free; > > > > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c > > index c57cb47..9463c7d 100644 > > --- a/tools/perf/util/symbol.c > > +++ b/tools/perf/util/symbol.c > > @@ -1687,11 +1687,16 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map) > > > > scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s/kallsyms", > > buildid_dir, sbuild_id); > > - > > + /* Try old style kallsyms cache */ > > if (access(path, F_OK)) { > > - pr_err("No kallsyms or vmlinux with build-id %s was found\n", > > - sbuild_id); > > - return NULL; > > + scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s", > > + buildid_dir, sbuild_id); > > + > > + if (access(path, F_OK)) { > > + pr_err("No kallsyms or vmlinux with build-id %s was found\n", > > + sbuild_id); > > + return NULL; > > + } > > } > > > > return strdup(path); -- Masami Hiramatsu