Messages in this thread | | | From | Arnaldo Carvalho de Melo <> | Date | Tue, 10 Mar 2020 10:06:44 -0300 | Subject | Re: [PATCH V2 1/9] perf pmu: Add support for PMU capabilities |
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Em Mon, Mar 09, 2020 at 10:46:31AM -0700, kan.liang@linux.intel.com escreveu: > From: Kan Liang <kan.liang@linux.intel.com> > > The PMU capabilities information, which is located at > /sys/bus/event_source/devices/<dev>/caps, is required by perf tool. > For example, the max LBR information is required to stitch LBR call > stack. > > Add perf_pmu__caps_parse() to parse the PMU capabilities information. > The information is stored in a list. > > Add perf_pmu__scan_caps() to scan the capabilities one by one. > > The following patch will store the capabilities information in perf > header. > > Reviewed-by: Andi Kleen <ak@linux.intel.com> > Signed-off-by: Kan Liang <kan.liang@linux.intel.com> > --- > tools/perf/util/pmu.c | 87 +++++++++++++++++++++++++++++++++++++++++++ > tools/perf/util/pmu.h | 12 ++++++ > 2 files changed, 99 insertions(+) > > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c > index 8b99fd312aae..13634ca09096 100644 > --- a/tools/perf/util/pmu.c > +++ b/tools/perf/util/pmu.c > @@ -844,6 +844,7 @@ static struct perf_pmu *pmu_lookup(const char *name) > > INIT_LIST_HEAD(&pmu->format); > INIT_LIST_HEAD(&pmu->aliases); > + INIT_LIST_HEAD(&pmu->caps); > list_splice(&format, &pmu->format); > list_splice(&aliases, &pmu->aliases); > list_add_tail(&pmu->list, &pmus); > @@ -1565,3 +1566,89 @@ int perf_pmu__scan_file(struct perf_pmu *pmu, const char *name, const char *fmt, > va_end(args); > return ret; > } > + > +static int perf_pmu__new_caps(struct list_head *list, char *name, char *value) > +{ > + struct perf_pmu_caps *caps; > + > + caps = zalloc(sizeof(*caps)); > + if (!caps) > + return -ENOMEM; > +
So here you check if zalloc fails and returns a proper error
> + caps->name = strdup(name); > + caps->value = strndup(value, strlen(value) - 1);
But then you don't check strdup()?
> + list_add_tail(&caps->list, list); > + return 0; > +} > + > +/* > + * Reading/parsing the given pmu capabilities, which should be located at: > + * /sys/bus/event_source/devices/<dev>/caps as sysfs group attributes. > + * Return the number of capabilities > + */ > +int perf_pmu__caps_parse(struct perf_pmu *pmu) > +{ > + struct stat st; > + char caps_path[PATH_MAX]; > + const char *sysfs = sysfs__mountpoint(); > + DIR *caps_dir; > + struct dirent *evt_ent; > + int nr_caps = 0; > + > + if (!sysfs) > + return -1; > + > + snprintf(caps_path, PATH_MAX, > + "%s" EVENT_SOURCE_DEVICE_PATH "%s/caps", sysfs, pmu->name); > + > + if (stat(caps_path, &st) < 0) > + return 0; /* no error if caps does not exist */ > + > + caps_dir = opendir(caps_path); > + if (!caps_dir) > + return -EINVAL; > + > + while ((evt_ent = readdir(caps_dir)) != NULL) { > + char path[PATH_MAX + NAME_MAX + 1]; > + char *name = evt_ent->d_name; > + char value[128]; > + FILE *file; > + > + if (!strcmp(name, ".") || !strcmp(name, "..")) > + continue; > + > + snprintf(path, sizeof(path), "%s/%s", caps_path, name); > + > + file = fopen(path, "r"); > + if (!file) > + break; > + > + if (!fgets(value, sizeof(value), file) || > + (perf_pmu__new_caps(&pmu->caps, name, value) < 0)) { > + fclose(file); > + break; > + } > + > + nr_caps++; > + fclose(file); > + } > + > + closedir(caps_dir); > + > + return nr_caps; > +} > + > +struct perf_pmu_caps *perf_pmu__scan_caps(struct perf_pmu *pmu, > + struct perf_pmu_caps *caps) > +{ > + if (!pmu) > + return NULL; > + > + if (!caps) > + caps = list_prepare_entry(caps, &pmu->caps, list); > + > + list_for_each_entry_continue(caps, &pmu->caps, list) > + return caps; > + > + return NULL; > +} > diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h > index 6737e3d5d568..a228e27ae462 100644 > --- a/tools/perf/util/pmu.h > +++ b/tools/perf/util/pmu.h > @@ -21,6 +21,12 @@ enum { > > struct perf_event_attr; > > +struct perf_pmu_caps { > + char *name; > + char *value; > + struct list_head list; > +}; > + > struct perf_pmu { > char *name; > __u32 type; > @@ -32,6 +38,7 @@ struct perf_pmu { > struct perf_cpu_map *cpus; > struct list_head format; /* HEAD struct perf_pmu_format -> list */ > struct list_head aliases; /* HEAD struct perf_pmu_alias -> list */ > + struct list_head caps; /* HEAD struct perf_pmu_caps -> list */ > struct list_head list; /* ELEM */ > }; > > @@ -102,4 +109,9 @@ struct pmu_events_map *perf_pmu__find_map(struct perf_pmu *pmu); > > int perf_pmu__convert_scale(const char *scale, char **end, double *sval); > > +int perf_pmu__caps_parse(struct perf_pmu *pmu); > + > +struct perf_pmu_caps *perf_pmu__scan_caps(struct perf_pmu *pmu, > + struct perf_pmu_caps *caps); > + > #endif /* __PMU_H */ > -- > 2.17.1 >
--
- Arnaldo
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