On 6/29/22 23:55, Ian Rogers wrote:
> New architectures bring new complexity, such as Intel's hybrid
> models. jevents provides an alternative to specifying events in the
> kernel and exposing them through sysfs, however, it is difficult to
> work with. For example, an error in the json input would yield an
> error message but no json file or location. It is also a challenge to
> update jsmn.c given its forked nature.
>
> The changes here switch from jevents.c to a rewrite in python called
> jevents.py. This means there is a build time dependency on python, but
> such a dependency already exists for asciidoc (used to generate perf's
> man pages). If the build detects that python isn't present or is older
> than version 3.6 (released Dec. 2016) then an empty file is
> substituted for the generated one.
>
> A challenge with this code is in avoiding regressions. For this reason
> the jevents.py produces identical output to jevents.c, validated with a
> test script and build target.
>
Patchset looks good to me.
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Kajol Jain <kjain@linux.ibm.com>
Thanks,
Kajol Jain
> v7. Adds Tested-by from John Garry <john.garry@huawei.com>.
> v6. Adds Tested-by from Zhengjun Xing <zhengjun.xing@linux.intel.com>
> and Thomas Richter <tmricht@linux.ibm.com>. Fixes issues spotted
> by Jiri Olsa <jolsa@kernel.org>, jsmn.c wasn't deleted and the
> empty pmu-events.c didn't pass the pmu-events test. It also adds a
> missing mkdir which is necessary before creating pmu-events.c and
> tweaks the quiet display code in the empty case to display a gen.
> v5. Adds a 2>/dev/null as suggested by David Laight
> <David.Laight@aculab.com>.
> v4. Fixes the build for systems with python2 installed by adding a
> patch that makes python3 the preferred python (Reported-by: John
> Garry <john.garry@huawei.com>). It also fixes a bash-ism in the
> jevents-test.sh and fixes the handling of an empty string for a
> metric BriefDescription as one was added for sapphirerapids in the
> metric Execute.
> v3. Updates the patches for merged changes (on
> acme/tmp.perf/core). Re-runs all comparisons to make sure the
> generated pmu-events.c isn't altered at all by this change. Adds
> the jevents.c ExtSel fix in:
> https://lore.kernel.org/lkml/20220525140410.1706851-1-zhengjun.xing@linux.intel.com/
> Bumps the python version from 3.5 to 3.6, as f-strings weren't
> introduced until 3.6.
> v2. Fixes the build for architectures that don't have pmu-events json
> (Suggested-by: John Garry <john.garry@huawei.com>) and fixes the
> build for python not being present or too old (Suggested-by: Peter
> Zijlstra <peterz@infradead.org>/John Garry <john.garry@huawei.com>).
>
> Ian Rogers (4):
> perf python: Prefer python3
> perf jevents: Add python converter script
> perf jevents: Switch build to use jevents.py
> perf jevents: Remove jevents.c
>
> tools/perf/Makefile.config | 27 +-
> tools/perf/Makefile.perf | 16 +-
> tools/perf/pmu-events/Build | 17 +-
> tools/perf/pmu-events/empty-pmu-events.c | 158 +++
> tools/perf/pmu-events/jevents.c | 1342 ----------------------
> tools/perf/pmu-events/jevents.py | 409 +++++++
> tools/perf/pmu-events/jsmn.c | 352 ------
> tools/perf/pmu-events/jsmn.h | 68 --
> tools/perf/pmu-events/json.c | 162 ---
> tools/perf/pmu-events/json.h | 39 -
> 10 files changed, 604 insertions(+), 1986 deletions(-)
> create mode 100644 tools/perf/pmu-events/empty-pmu-events.c
> delete mode 100644 tools/perf/pmu-events/jevents.c
> create mode 100755 tools/perf/pmu-events/jevents.py
> delete mode 100644 tools/perf/pmu-events/jsmn.c
> delete mode 100644 tools/perf/pmu-events/jsmn.h
> delete mode 100644 tools/perf/pmu-events/json.c
> delete mode 100644 tools/perf/pmu-events/json.h
>