Re: [PATCH V5] perf tools: adding support for address filters

[Mathieu Poirier]

On 13 September 2016 at 04:01, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> On 12/09/16 20:53, Mathieu Poirier wrote:
>> This patch makes it possible to use the current filter
>> framework with address filters.  That way address filters for
>> HW tracers such as CoreSight and IntelPT can be communicated
>> to the kernel drivers.
>>
>> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>>
>> ---
>> Changes for V5:
>>  - Modified perf_evsel__append_filter() to take a string format
>>    rather than an operation.
>
> Hope I'm not being a pain, but aren't there other places calling
> perf_evsel__append_filter() that need to be changed.  Might make
> sense as a separate patch.

No no, you're right - I completely overlooked that.

But shouldn't it be in the same patch?  That way a git bisect would
stay consistent...

>
>>
>> Changes for V4:
>>  - Added support for address filters over more than one
>>    nibble.
>>  - Removed Jiri's ack, this version is too different from
>>    what was reviewed.
>>
>> Changes for V3:
>>  - Added Jiri's ack.
>>  - Rebased to v4.8-rc5.
>>
>> Changes for V2:
>>  - Rebased to v4.8-rc4.
>>  - Revisited error path.
>>
>>
>>  tools/perf/util/evsel.c        |  4 ++--
>>  tools/perf/util/evsel.h        |  2 +-
>>  tools/perf/util/parse-events.c | 40 +++++++++++++++++++++++++++++++++++-----
>>  3 files changed, 38 insertions(+), 8 deletions(-)
>>
>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>> index d40f852d2de2..a9bb277f221f 100644
>> --- a/tools/perf/util/evsel.c
>> +++ b/tools/perf/util/evsel.c
>> @@ -1047,14 +1047,14 @@ int perf_evsel__set_filter(struct perf_evsel *evsel, const char *filter)
>>  }
>>
>>  int perf_evsel__append_filter(struct perf_evsel *evsel,
>> -                           const char *op, const char *filter)
>> +                           const char *fmt, const char *filter)
>>  {
>>       char *new_filter;
>>
>>       if (evsel->filter == NULL)
>>               return perf_evsel__set_filter(evsel, filter);
>>
>> -     if (asprintf(&new_filter,"(%s) %s (%s)", evsel->filter, op, filter) > 0) {
>> +     if (asprintf(&new_filter, fmt, evsel->filter, filter) > 0) {
>>               free(evsel->filter);
>>               evsel->filter = new_filter;
>>               return 0;
>> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
>> index 8ceb7ebb51f5..50595c8c7207 100644
>> --- a/tools/perf/util/evsel.h
>> +++ b/tools/perf/util/evsel.h
>> @@ -236,7 +236,7 @@ void perf_evsel__set_sample_id(struct perf_evsel *evsel,
>>
>>  int perf_evsel__set_filter(struct perf_evsel *evsel, const char *filter);
>>  int perf_evsel__append_filter(struct perf_evsel *evsel,
>> -                           const char *op, const char *filter);
>> +                           const char *fmt, const char *filter);
>>  int perf_evsel__apply_filter(struct perf_evsel *evsel, int ncpus, int nthreads,
>>                            const char *filter);
>>  int perf_evsel__apply_drv_configs(struct perf_evsel *evsel,
>> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
>> index 2eb8b1ed4cc8..8e683979ccd8 100644
>> --- a/tools/perf/util/parse-events.c
>> +++ b/tools/perf/util/parse-events.c
>> @@ -1760,20 +1760,50 @@ foreach_evsel_in_last_glob(struct perf_evlist *evlist,
>>  static int set_filter(struct perf_evsel *evsel, const void *arg)
>>  {
>>       const char *str = arg;
>> +     bool found = false;
>> +     int nr_addr_filters = 0;
>> +     struct perf_pmu *pmu = NULL;
>>
>> -     if (evsel == NULL || evsel->attr.type != PERF_TYPE_TRACEPOINT) {
>> -             fprintf(stderr,
>> -                     "--filter option should follow a -e tracepoint option\n");
>> -             return -1;
>> +     if (evsel == NULL)
>> +             goto err;
>> +
>> +     if (evsel->attr.type == PERF_TYPE_TRACEPOINT) {
>> +             if (perf_evsel__append_filter(evsel,
>> +                                           "(%s) && (%s)", str) < 0) {
>> +                     fprintf(stderr,
>> +                             "not enough memory to hold filter string\n");
>> +                     return -1;
>> +             }
>> +
>> +             return 0;
>>       }
>>
>> -     if (perf_evsel__append_filter(evsel, "&&", str) < 0) {
>> +     while ((pmu = perf_pmu__scan(pmu)) != NULL)
>> +             if (pmu->type == evsel->attr.type) {
>> +                     found = true;
>> +                     break;
>> +             }
>> +
>> +     if (found)
>> +             perf_pmu__scan_file(pmu, "nr_addr_filters",
>> +                                 "%d", &nr_addr_filters);
>> +
>> +     if (!nr_addr_filters)
>> +             goto err;
>> +
>> +     if (perf_evsel__append_filter(evsel, "%s,%s", str) < 0) {
>>               fprintf(stderr,
>>                       "not enough memory to hold filter string\n");
>>               return -1;
>>       }
>>
>>       return 0;
>> +
>> +err:
>> +     fprintf(stderr,
>> +             "--filter option should follow a -e tracepoint or HW tracer option\n");
>> +
>> +     return -1;
>>  }
>>
>>  int parse_filter(const struct option *opt, const char *str,
>>
>