perf tools: Refactor unit and scale function parameters

Passing pointers to alias modifiers 'unit' and 'scale' isn't very
future-proof since if we add more modifiers to the list we'll end up
passing more arguments.

Instead wrap everything up in a struct perf_pmu_info, which can easily
be expanded when additional alias modifiers are necessary in the future.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1411567455-31264-3-git-send-email-matt@console-pimps.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 33 insertions, 21 deletions

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 61be3e695ec2..9522cf22ad81 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -634,10 +634,9 @@ int parse_events_add_pmu(struct list_head *list, int *idx,
                          char *name, struct list_head *head_config)
 {
         struct perf_event_attr attr;
+        struct perf_pmu_info info;
         struct perf_pmu *pmu;
         struct perf_evsel *evsel;
-        const char *unit;
-        double scale;
 
         pmu = perf_pmu__find(name);
         if (!pmu)
@@ -656,7 +655,7 @@ int parse_events_add_pmu(struct list_head *list, int *idx,
                 return evsel ? 0 : -ENOMEM;
         }
 
-        if (perf_pmu__check_alias(pmu, head_config, &unit, &scale))
+        if (perf_pmu__check_alias(pmu, head_config, &info))
                 return -EINVAL;
 
         /*
@@ -671,8 +670,8 @@ int parse_events_add_pmu(struct list_head *list, int *idx,
         evsel = __add_event(list, idx, &attr, pmu_event_name(head_config),
                             pmu->cpus);
         if (evsel) {
-                evsel->unit = unit;
-                evsel->scale = scale;
+                evsel->unit = info.unit;
+                evsel->scale = info.scale;
         }
 
         return evsel ? 0 : -ENOMEM;
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 22a4ad5a927a..93a41ca96b8e 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -210,6 +210,19 @@ static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FI
         return 0;
 }
 
+static inline bool pmu_alias_info_file(char *name)
+{
+        size_t len;
+
+        len = strlen(name);
+        if (len > 5 && !strcmp(name + len - 5, ".unit"))
+                return true;
+        if (len > 6 && !strcmp(name + len - 6, ".scale"))
+                return true;
+
+        return false;
+}
+
 /*
  * Process all the sysfs attributes located under the directory
  * specified in 'dir' parameter.
@@ -218,7 +231,6 @@ static int pmu_aliases_parse(char *dir, struct list_head *head)
 {
         struct dirent *evt_ent;
         DIR *event_dir;
-        size_t len;
         int ret = 0;
 
         event_dir = opendir(dir);
@@ -234,13 +246,9 @@ static int pmu_aliases_parse(char *dir, struct list_head *head)
                         continue;
 
                 /*
-                 * skip .unit and .scale info files
-                 * parsed in perf_pmu__new_alias()
+                 * skip info files parsed in perf_pmu__new_alias()
                  */
-                len = strlen(name);
-                if (len > 5 && !strcmp(name + len - 5, ".unit"))
-                        continue;
-                if (len > 6 && !strcmp(name + len - 6, ".scale"))
+                if (pmu_alias_info_file(name))
                         continue;
 
                 snprintf(path, PATH_MAX, "%s/%s", dir, name);
@@ -645,7 +653,7 @@ static int check_unit_scale(struct perf_pmu_alias *alias,
  * defined for the alias
  */
 int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
-                          const char **unit, double *scale)
+                          struct perf_pmu_info *info)
 {
         struct parse_events_term *term, *h;
         struct perf_pmu_alias *alias;
@@ -655,8 +663,8 @@ 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)
          */
-        *unit   = NULL;
-        *scale  = 0.0;
+        info->unit   = NULL;
+        info->scale  = 0.0;
 
         list_for_each_entry_safe(term, h, head_terms, list) {
                 alias = pmu_find_alias(pmu, term);
@@ -666,7 +674,7 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
                 if (ret)
                         return ret;
 
-                ret = check_unit_scale(alias, unit, scale);
+                ret = check_unit_scale(alias, &info->unit, &info->scale);
                 if (ret)
                         return ret;
 
@@ -679,11 +687,11 @@ int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
          * set defaults as for evsel
          * unit cannot left to NULL
          */
-        if (*unit == NULL)
-                *unit   = "";
+        if (info->unit == NULL)
+                info->unit   = "";
 
-        if (*scale == 0.0)
-                *scale  = 1.0;
+        if (info->scale == 0.0)
+                info->scale  = 1.0;
 
         return 0;
 }
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 0f5c0a88fdc8..fe90a012c003 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -25,6 +25,11 @@ struct perf_pmu {
         struct list_head list;    /* ELEM */
 };
 
+struct perf_pmu_info {
+        const char *unit;
+        double scale;
+};
+
 struct perf_pmu *perf_pmu__find(const char *name);
 int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
                      struct list_head *head_terms);
@@ -33,7 +38,7 @@ int perf_pmu__config_terms(struct list_head *formats,
                            struct list_head *head_terms,
                            bool zero);
 int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
-                          const char **unit, double *scale);
+                          struct perf_pmu_info *info);
 struct list_head *perf_pmu__alias(struct perf_pmu *pmu,
                                   struct list_head *head_terms);
 int perf_pmu_wrap(void);