On 30/06/15 07:58, Ingo Molnar wrote: > > * Arnaldo Carvalho de Melo <a...@kernel.org> 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 <a...@redhat.com> >> >> ---------------------------------------------------------------- >> 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 [<options>] [<command>] > or: perf record [<options>] -- <command> [<options>] > > -e, --event <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.
That is not entirely true. The message says "Run 'perf list' for a list of valid events" which will tell you if the event is valid. So you can tell the difference between a typo and unsupported event. > > 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? 'perf list' shows the event wasn't supported, so I am not sure what more the "newbie" could expect. Do you have any suggestions? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/