[PATCH v8 0/4] perf tools: add support for libpfm4

Ian Rogers
2020-04-11T07:46:40Z

This patch links perf with the libpfm4 library if it is available
and NO_LIBPFM4 isn't passed to the build. The libpfm4 library
contains hardware event tables for all processors supported by
perf_events. It is a helper library that helps convert from a
symbolic event name to the event encoding required by the
underlying kernel interface. This library is open-source and
available from: http://perfmon2.sf.net.

With this patch, it is possible to specify full hardware events
by name. Hardware filters are also supported. Events must be
specified via the --pfm-events and not -e option. Both options
are active at the same time and it is possible to mix and match:

$ perf stat --pfm-events inst_retired:any_p:c=1:i -e cycles ....

v8 addresses review comments from jolsa@redhat.com.
Breaks the patch into 4, adds a test and moves the libpfm code into its
own file. perf list encoding tries to be closer to existing:
...
skx pfm-events
UNHALTED_CORE_CYCLES
[Count core clock cycles whenever the clock signal on the specific ...
UNHALTED_REFERENCE_CYCLES
[Unhalted reference cycles]
INSTRUCTION_RETIRED
[Number of instructions at retirement]
INSTRUCTIONS_RETIRED
[This is an alias for INSTRUCTION_RETIRED]
BRANCH_INSTRUCTIONS_RETIRED
[Count branch instructions at retirement. Specifically, this event ...
MISPREDICTED_BRANCH_RETIRED
[Count mispredicted branch instructions at retirement. ...
BACLEARS
[Branch re-steered]
BACLEARS:ANY
[Number of front-end re-steers due to BPU misprediction]
BR_INST_RETIRED
[Branch instructions retired (Precise Event)]
BR_INST_RETIRED:CONDITIONAL
[Counts all taken and not taken macro conditional branch ...
...
and supports --long-desc/-v:
...
BACLEARS
[Branch re-steered]
Code : 0xe6
BACLEARS:ANY
[Number of front-end re-steers due to BPU misprediction]
Umask : 0x01 : PMU: [default]
Modif : PMU: [e] : edge level (may require counter-mask >= 1) ...
Modif : PMU: [i] : invert (boolean)
Modif : PMU: [c] : counter-mask in range [0-255] (integer)
Modif : PMU: [t] : measure any thread (boolean)
Modif : PMU: [intx] : monitor only inside transactional memory ...
Modif : PMU: [intxcp] : do not count occurrences inside aborted ...
Modif : perf_event: [u] : monitor at user level (boolean)
Modif : perf_event: [k] : monitor at kernel level (boolean)
Modif : perf_event: [period] : sampling period (integer)
Modif : perf_event: [freq] : sampling frequency (Hz) (integer)
Modif : perf_event: [excl] : exclusive access (boolean)
Modif : perf_event: [mg] : monitor guest execution (boolean)
Modif : perf_event: [mh] : monitor host execution (boolean)
Modif : perf_event: [cpu] : CPU to program (integer)
Modif : perf_event: [pinned] : pin event to counters (boolean)
BR_INST_RETIRED
[Branch instructions retired (Precise Event)]
Code : 0xc4
BR_INST_RETIRED:CONDITIONAL
[Counts all taken and not taken macro conditional branch ...
Umask : 0x01 : PMU: [precise]

v7 rebases and adds fallback code for libpfm4 events.
The fallback code is to force user only priv level in case the
perf_event_open() syscall failed for permissions reason.
the fallback forces a user privilege level restriction on the event
string, so depending on the syntax either u or :u is needed.

But libpfm4 can use a : or . as the separator, so simply searching
for ':' vs. '/' is not good enough to determine the syntax needed.
Therefore, this patch introduces a new evsel boolean field to mark
events coming from libpfm4. The field is then used to adjust the
fallback string.
v6 was a rebase.
v5 was a rebase.
v4 was a rebase on
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git
branch perf/core and re-adds the tools/build/feature/test-libpfm4.c
missed in v3.
v3 is against acme/perf/core and removes a diagnostic warning.
v2 of this patch makes the --pfm-events man page documentation
conditional on libpfm4 behing configured. It tidies some of the
documentation and adds the feature test missed in the v1 patch.

Ian Rogers (1):
perf doc: allow ASCIIDOC_EXTRA to be an argument

Stephane Eranian (3):
tools feature: add support for detecting libpfm4
perf pmu: add perf_pmu__find_by_type helper
perf tools: add support for libpfm4

tools/build/Makefile.feature | 6 +-
tools/build/feature/Makefile | 6 +-
tools/build/feature/test-libpfm4.c | 9 +
tools/perf/Documentation/Makefile | 4 +-
tools/perf/Documentation/perf-record.txt | 11 +
tools/perf/Documentation/perf-stat.txt | 10 +
tools/perf/Documentation/perf-top.txt | 11 +
tools/perf/Makefile.config | 12 +
tools/perf/Makefile.perf | 6 +-
tools/perf/builtin-list.c | 14 +-
tools/perf/builtin-record.c | 13 ++
tools/perf/builtin-stat.c | 13 ++
tools/perf/builtin-top.c | 13 ++
tools/perf/tests/Build | 1 +
tools/perf/tests/builtin-test.c | 9 +
tools/perf/tests/pfm.c | 206 +++++++++++++++++
tools/perf/tests/tests.h | 3 +
tools/perf/util/Build | 2 +
tools/perf/util/evsel.c | 6 +
tools/perf/util/evsel.h | 3 +
tools/perf/util/parse-events.c | 37 ++-
tools/perf/util/parse-events.h | 5 +
tools/perf/util/pfm.c | 272 +++++++++++++++++++++++
tools/perf/util/pfm.h | 19 ++
tools/perf/util/pmu.c | 11 +
tools/perf/util/pmu.h | 1 +
26 files changed, 687 insertions(+), 16 deletions(-)
create mode 100644 tools/build/feature/test-libpfm4.c
create mode 100644 tools/perf/tests/pfm.c
create mode 100644 tools/perf/util/pfm.c
create mode 100644 tools/perf/util/pfm.h

--
2.26.0.110.g2183baf09c-goog