4 files changed, 40 insertions, 11 deletions

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 792b0ea8a8b8..b18d58da580b 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -73,6 +73,7 @@ struct perf_evsel {
         char                    *name;
         double                  scale;
         const char              *unit;
+        bool                    snapshot;
         struct event_format     *tp_format;
         union {
                 void            *priv;
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 5a373483f0e4..77b43fe43d55 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -682,6 +682,7 @@ int parse_events_add_pmu(struct list_head *list, int *idx,
                 evsel->unit = info.unit;
                 evsel->scale = info.scale;
                 evsel->per_pkg = info.per_pkg;
+                evsel->snapshot = info.snapshot;
         }
 
         return evsel ? 0 : -ENOMEM;
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index f003b5a9e059..5c9c4947cfb4 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -181,6 +181,23 @@ perf_pmu__parse_per_pkg(struct perf_pmu_alias *alias, char *dir, char *name)
         return 0;
 }
 
+static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
+                                    char *dir, char *name)
+{
+        char path[PATH_MAX];
+        int fd;
+
+        snprintf(path, PATH_MAX, "%s/%s.snapshot", dir, name);
+
+        fd = open(path, O_RDONLY);
+        if (fd == -1)
+                return -1;
+
+        alias->snapshot = true;
+        close(fd);
+        return 0;
+}
+
 static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FILE *file)
 {
         struct perf_pmu_alias *alias;
@@ -214,6 +231,7 @@ static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FI
         perf_pmu__parse_unit(alias, dir, name);
         perf_pmu__parse_scale(alias, dir, name);
         perf_pmu__parse_per_pkg(alias, dir, name);
+        perf_pmu__parse_snapshot(alias, dir, name);
 
         list_add_tail(&alias->list, list);
 
@@ -231,6 +249,8 @@ static inline bool pmu_alias_info_file(char *name)
                 return true;
         if (len > 8 && !strcmp(name + len - 8, ".per-pkg"))
                 return true;
+        if (len > 9 && !strcmp(name + len - 9, ".snapshot"))
+                return true;
 
         return false;
 }
@@ -639,23 +659,27 @@ static struct perf_pmu_alias *pmu_find_alias(struct perf_pmu *pmu,
 }
 
 
-static int check_unit_scale(struct perf_pmu_alias *alias,
-                            const char **unit, double *scale)
+static int check_info_data(struct perf_pmu_alias *alias,
+                           struct perf_pmu_info *info)
 {
         /*
          * Only one term in event definition can
-         * define unit and scale, fail if there's
-         * more than one.
+         * define unit, scale and snapshot, fail
+         * if there's more than one.
          */
-        if ((*unit && alias->unit) ||
-            (*scale && alias->scale))
+        if ((info->unit && alias->unit) ||
+            (info->scale && alias->scale) ||
+            (info->snapshot && alias->snapshot))
                 return -EINVAL;
 
         if (alias->unit)
-                *unit = alias->unit;
+                info->unit = alias->unit;
 
         if (alias->scale)
-                *scale = alias->scale;
+                info->scale = alias->scale;
+
+        if (alias->snapshot)
+                info->snapshot = alias->snapshot;
 
         return 0;
 }
@@ -677,8 +701,9 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
          * Mark unit and scale as not set
          * (different from default values, see below)
          */
-        info->unit   = NULL;
-        info->scale  = 0.0;
+        info->unit     = NULL;
+        info->scale    = 0.0;
+        info->snapshot = false;
 
         list_for_each_entry_safe(term, h, head_terms, list) {
                 alias = pmu_find_alias(pmu, term);
@@ -688,7 +713,7 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
                 if (ret)
                         return ret;
 
-                ret = check_unit_scale(alias, &info->unit, &info->scale);
+                ret = check_info_data(alias, info);
                 if (ret)
                         return ret;
 
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index c3a74e0e17a2..6b1249fbdb5f 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -30,6 +30,7 @@ struct perf_pmu_info {
         const char *unit;
         double scale;
         bool per_pkg;
+        bool snapshot;
 };
 
 #define UNIT_MAX_LEN    31 /* max length for event unit name */
@@ -41,6 +42,7 @@ struct perf_pmu_alias {
         char unit[UNIT_MAX_LEN+1];
         double scale;
         bool per_pkg;
+        bool snapshot;
 };
 
 struct perf_pmu *perf_pmu__find(const char *name);