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

[Adrian Hunter]

On 13/09/16 17:18, Mathieu Poirier wrote:
> 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...

I meant changing perf_evsel__append_filter() and callers in a separate
preparatory patch.  Perhaps add and use:

int perf_evsel__append_tp_filter(struct perf_evsel *evsel, const char *filter)
{
	return perf_evsel__append_filter(evsel, "(%s) && (%s)", filter);
}

> 
>>
>>>
>>> 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,
>>>
>>
>