[PATCH v2 02/11] perf tools: Refactor unit and scale function parameters

From: Matt Fleming
Date: Wed Oct 01 2014 - 10:36:52 EST


From: Matt Fleming <matt.fleming@xxxxxxxxx>

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.

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
---

Changes in v2:
- Added Jiri's ACK

tools/perf/util/parse-events.c | 9 ++++-----
tools/perf/util/pmu.c | 38 +++++++++++++++++++++++---------------
tools/perf/util/pmu.h | 7 ++++++-
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);
--
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/