[PATCH 4/8] perf tools: Read and store caps/max_precise in perf_pmu

Jiri Olsa
2019-03-05T15:25:54Z

Read the caps/max_precise value and store it in struct
perf_pmu to be used when setting the maximum precise_ip
field in following patch.

Link: http://lkml.kernel.org/n/tip-y47h37fzs5t8hy9t0j5g9pyj@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/util/pmu.c | 14 ++++++++++++++
tools/perf/util/pmu.h | 1 +
2 files changed, 15 insertions(+)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 51d437f55d18..6199a3174ab9 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -752,6 +752,19 @@ perf_pmu__get_default_config(struct perf_pmu *pmu __maybe_unused)
return NULL;
}

+static int pmu_max_precise(const char *name)
+{
+ char path[PATH_MAX];
+ int max_precise = -1;
+
+ scnprintf(path, PATH_MAX,
+ "bus/event_source/devices/%s/caps/max_precise",
+ name);
+
+ sysfs__read_int(path, &max_precise);
+ return max_precise;
+}
+
static struct perf_pmu *pmu_lookup(const char *name)
{
struct perf_pmu *pmu;
@@ -784,6 +797,7 @@ static struct perf_pmu *pmu_lookup(const char *name)
pmu->name = strdup(name);
pmu->type = type;
pmu->is_uncore = pmu_is_uncore(name);
+ pmu->max_precise = pmu_max_precise(name);
pmu_add_cpu_aliases(&aliases, pmu);

INIT_LIST_HEAD(&pmu->format);
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 47253c3daf55..bd9ec2704a57 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -26,6 +26,7 @@ struct perf_pmu {
__u32 type;
bool selectable;
bool is_uncore;
+ int max_precise;
struct perf_event_attr *default_config;
struct cpu_map *cpus;
struct list_head format; /* HEAD struct perf_pmu_format -> list */
--
2.17.2