From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754485AbbF3E7M (ORCPT ); Tue, 30 Jun 2015 00:59:12 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:35596 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752880AbbF3E65 (ORCPT ); Tue, 30 Jun 2015 00:58:57 -0400 Date: Tue, 30 Jun 2015 06:58:52 +0200 From: Ingo Molnar To: Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, Adrian Hunter , Jiri Olsa , David Ahern , Namhyung Kim , Peter Zijlstra , Stephane Eranian , Arnaldo Carvalho de Melo Subject: Re: [GIT PULL 0/8] perf/pt -> Intel PT/BTS Message-ID: <20150630045852.GB31981@gmail.com> References: <1435356140-31212-1-git-send-email-acme@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1435356140-31212-1-git-send-email-acme@kernel.org> 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 * Arnaldo Carvalho de Melo wrote: > Hi Ingo, > > Please consider pulling, there are several other patches after this, > but I think that this may be acceptable to showcase the capabilities already > present, look at the output of 'perf script' and callchains for userspace > without using any extra debugging info (no need for DWARF, CFI, nothing), > really cool capabilities... :-) > > Adrian wrote some docs and I tested it both on a Ivy Bridge machine > where there is only BTS and on a Broadwell machine with the whole shebang, > adding the output of the commands to the csets, to further showcase what is > there already. > > This is on top of my last perf-core-for-mingo tag. > > Up to you, please let us know what you think and we'll continue working > on having this in an acceptable form for merging, > > Regards, > > - Arnaldo > > P.S. Kudos for Adrian for the patience with this process, way more is needed to > polish this, but the promise is there, cool stuff indeed! :-) > > The following changes since commit 36c8bb56a9f718a9a5f35d1834ca9dcec95deb4a: > > perf symbols: Check access permission when reading symbol files (2015-06-26 12:11:53 -0300) > > are available in the git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-pt-for-mingo > > for you to fetch changes up to 04759f172270afb28c8004f5cad62ed55710a499: > > perf tools: Add Intel BTS support (2015-06-26 18:36:11 -0300) > > ---------------------------------------------------------------- > Put Intel PT and BTS into initial use (Adrian Hunter) > > Signed-off-by: Arnaldo Carvalho de Melo > > ---------------------------------------------------------------- > Adrian Hunter (8): > perf auxtrace: Add Intel PT as an AUX area tracing type > perf tools: Add Intel PT packet decoder > perf tools: Add Intel PT instruction decoder > perf tools: Add Intel PT log > perf tools: Add Intel PT decoder > perf tools: Add Intel PT support > perf tools: Take Intel PT into use > perf tools: Add Intel BTS support > > tools/build/Makefile.build | 2 + > tools/perf/.gitignore | 2 + > tools/perf/Documentation/intel-bts.txt | 86 + > tools/perf/Documentation/intel-pt.txt | 588 ++++++ > tools/perf/MANIFEST | 7 + > tools/perf/Makefile.perf | 12 +- > tools/perf/arch/x86/util/Build | 5 + > tools/perf/arch/x86/util/auxtrace.c | 83 + > tools/perf/arch/x86/util/intel-bts.c | 458 +++++ > tools/perf/arch/x86/util/intel-pt.c | 752 ++++++++ > tools/perf/arch/x86/util/pmu.c | 18 + > tools/perf/util/Build | 3 + > tools/perf/util/auxtrace.c | 9 +- > tools/perf/util/auxtrace.h | 2 + > tools/perf/util/intel-bts.c | 791 ++++++++ > tools/perf/util/intel-bts.h | 43 + > tools/perf/util/intel-pt-decoder/Build | 14 + > .../perf/util/intel-pt-decoder/intel-pt-decoder.c | 1759 ++++++++++++++++++ > .../perf/util/intel-pt-decoder/intel-pt-decoder.h | 102 ++ > .../util/intel-pt-decoder/intel-pt-insn-decoder.c | 246 +++ > .../util/intel-pt-decoder/intel-pt-insn-decoder.h | 65 + > tools/perf/util/intel-pt-decoder/intel-pt-log.c | 155 ++ > tools/perf/util/intel-pt-decoder/intel-pt-log.h | 52 + > .../util/intel-pt-decoder/intel-pt-pkt-decoder.c | 400 +++++ > .../util/intel-pt-decoder/intel-pt-pkt-decoder.h | 64 + > tools/perf/util/intel-pt.c | 1889 ++++++++++++++++++++ > tools/perf/util/intel-pt.h | 51 + > tools/perf/util/pmu.c | 4 - > 28 files changed, 7655 insertions(+), 7 deletions(-) > create mode 100644 tools/perf/Documentation/intel-bts.txt > create mode 100644 tools/perf/Documentation/intel-pt.txt > create mode 100644 tools/perf/arch/x86/util/auxtrace.c > create mode 100644 tools/perf/arch/x86/util/intel-bts.c > create mode 100644 tools/perf/arch/x86/util/intel-pt.c > create mode 100644 tools/perf/arch/x86/util/pmu.c > create mode 100644 tools/perf/util/intel-bts.c > create mode 100644 tools/perf/util/intel-bts.h > create mode 100644 tools/perf/util/intel-pt-decoder/Build > create mode 100644 tools/perf/util/intel-pt-decoder/intel-pt-decoder.c > create mode 100644 tools/perf/util/intel-pt-decoder/intel-pt-decoder.h > create mode 100644 tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c > create mode 100644 tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.h > create mode 100644 tools/perf/util/intel-pt-decoder/intel-pt-log.c > create mode 100644 tools/perf/util/intel-pt-decoder/intel-pt-log.h > create mode 100644 tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.c > create mode 100644 tools/perf/util/intel-pt-decoder/intel-pt-pkt-decoder.h > create mode 100644 tools/perf/util/intel-pt.c > create mode 100644 tools/perf/util/intel-pt.h Yeah, so I did a 'newbie test': I pulled the tree and saw that it has a tools/perf/Documentation/intel-bts.txt file and started reading it. Based on its text: The Intel BTS kernel driver creates a new PMU for Intel BTS. The perf record option is: -e intel_bts// Currently Intel BTS is limited to per-thread tracing so the --per-thread option is also needed. I tried the following command which failed: triton:~/tip> perf record -e intel_bts// --per-thread sleep 1 invalid or unsupported event: 'intel_bts//' Run 'perf list' for a list of valid events usage: perf record [] [] or: perf record [] -- [] -e, --event event selector. use 'perf list' to list available events That's a really ... unhelpful message. If I typoed something I want to know that. If the kernel does not support something, I want to know about that too. Tooling telling me: "maybe you typoed something, maybe it's not supported, I really don't care" is not very productive. So this was with a distro kernel, and in the hope that I'm missing some magic new kernel feature, I tried it the latest -tip kernel, but it still gives me the same failure. So the test newbie user got stuck after wasting some time. Me as a kernel developer could probably figure it out, but that's not the point: if newbies cannot discover and use our new features then it's as if they didn't exist, and I'm not pulling non-existent features! ;-) Could we please improve all this? Thanks, Ingo