[PATCH V2 2/3] perf tools: parse the pmu event prefix and surfix

From: kan . liang
Date: Tue Aug 26 2014 - 22:41:37 EST


From: Kan Liang <kan.liang@xxxxxxxxx>

There are two types of event formats for PMU events. E.g. el-abort OR
perf tools: parse the pmu event prefix and surfix

There are two types of event formats for PMU events. E.g. el-abort OR
cpu/el-abort/. However, the lexer mistakenly recognizes the simple style
format as two events.

The parse_events_pmu_check function uses bsearch to search the name in
known pmu event list. It can tell the lexer that the name is a PE_NAME
or a PMU event name prefix or a PMU event name suffix. All these
information will be used for accurately parsing kernel PMU events.

The pmu events list will be read from sysfs at runtime.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
---
V2: Read kernel PMU events from sysfs at runtime

tools/perf/util/parse-events.c | 103 +++++++++++++++++++++++++++++++++++++++++
tools/perf/util/parse-events.h | 15 ++++++
tools/perf/util/pmu.c | 10 ----
tools/perf/util/pmu.h | 10 ++++
4 files changed, 128 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 7a0aa75..5e69e65 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -29,6 +29,9 @@ extern int parse_events_debug;
#endif
int parse_events_parse(void *data, void *scanner);

+static struct kernel_pmu_event_symbol *kernel_pmu_events_list;
+static size_t kernel_pmu_events_list_num;
+
static struct event_symbol event_symbols_hw[PERF_COUNT_HW_MAX] = {
[PERF_COUNT_HW_CPU_CYCLES] = {
.symbol = "cpu-cycles",
@@ -852,6 +855,103 @@ int parse_events_name(struct list_head *list, char *name)
return 0;
}

+static int
+comp_pmu(const void *p1, const void *p2)
+{
+ struct kernel_pmu_event_symbol *pmu1 =
+ (struct kernel_pmu_event_symbol *) p1;
+ struct kernel_pmu_event_symbol *pmu2 =
+ (struct kernel_pmu_event_symbol *) p2;
+
+ return strcmp(pmu1->symbol, pmu2->symbol);
+}
+
+enum kernel_pmu_event_type
+parse_events_pmu_check(const char *name)
+{
+ struct kernel_pmu_event_symbol p, *r;
+
+ /*
+ * name "cpu" could be prefix of cpu-cycles or cpu// events.
+ * cpu-cycles has been handled by hardcode.
+ * So it must be cpu// events, not kernel pmu event.
+ */
+ if (!kernel_pmu_events_list_num || !strcmp(name, "cpu"))
+ return NONE_KERNEL_PMU_EVENT;
+
+ strcpy(p.symbol, name);
+ r = bsearch(&p, kernel_pmu_events_list,
+ kernel_pmu_events_list_num,
+ sizeof(struct kernel_pmu_event_symbol), comp_pmu);
+ if (r == NULL)
+ return NONE_KERNEL_PMU_EVENT;
+ return r->type;
+}
+
+/*
+ * Read the pmu events list from sysfs
+ * Save it into kernel_pmu_events_list
+ */
+static void scan_kernel_pmu_events_list(void)
+{
+
+ struct perf_pmu *pmu = NULL;
+ struct perf_pmu_alias *alias;
+ int len = 0;
+
+ while ((pmu = perf_pmu__scan(pmu)) != NULL)
+ list_for_each_entry(alias, &pmu->aliases, list) {
+ if (!strcmp(pmu->name, "cpu")) {
+ if (strchr(alias->name, '-'))
+ len++;
+ len++;
+ }
+ }
+ if (len == 0)
+ return;
+ kernel_pmu_events_list =
+ malloc(sizeof(struct kernel_pmu_event_symbol) * len);
+ kernel_pmu_events_list_num = len;
+
+ pmu = NULL;
+ len = 0;
+ while ((pmu = perf_pmu__scan(pmu)) != NULL)
+ list_for_each_entry(alias, &pmu->aliases, list) {
+ if (!strcmp(pmu->name, "cpu")) {
+ struct kernel_pmu_event_symbol *p =
+ kernel_pmu_events_list + len;
+ char *tmp = strchr(alias->name, '-');
+
+ if (tmp != NULL) {
+ strncpy(p->symbol, alias->name,
+ tmp - alias->name);
+ p->type = KERNEL_PMU_EVENT_PREFIX;
+ tmp++;
+ p++;
+ strcpy(p->symbol, tmp);
+ p->type = KERNEL_PMU_EVENT_SUFFIX;
+ len += 2;
+ } else {
+ strcpy(p->symbol, alias->name);
+ p->type = KERNEL_PMU_EVENT;
+ len++;
+ }
+ }
+ }
+ qsort(kernel_pmu_events_list, len,
+ sizeof(struct kernel_pmu_event_symbol), comp_pmu);
+
+}
+
+static void release_kernel_pmu_events_list(void)
+{
+ if (kernel_pmu_events_list) {
+ free(kernel_pmu_events_list);
+ kernel_pmu_events_list = NULL;
+ }
+ kernel_pmu_events_list_num = 0;
+}
+
static int parse_events__scanner(const char *str, void *data, int start_token)
{
YY_BUFFER_STATE buffer;
@@ -905,7 +1005,10 @@ int parse_events(struct perf_evlist *evlist, const char *str)
};
int ret;

+ /* scan kernel pmu events from sysfs */
+ scan_kernel_pmu_events_list();
ret = parse_events__scanner(str, &data, PE_START_EVENTS);
+ release_kernel_pmu_events_list();
if (!ret) {
int entries = data.idx - evlist->nr_entries;
perf_evlist__splice_list_tail(evlist, &data.list, entries);
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index df094b4..d06fec4 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -35,6 +35,19 @@ extern int parse_filter(const struct option *opt, const char *str, int unset);

#define EVENTS_HELP_MAX (128*1024)

+#define KERNEL_PMU_EVENT_MAX 1024
+enum kernel_pmu_event_type {
+ NONE_KERNEL_PMU_EVENT, /* not a PMU EVENT */
+ KERNEL_PMU_EVENT, /* normal style PMU event */
+ KERNEL_PMU_EVENT_PREFIX, /* prefix of pre-suf style event */
+ KERNEL_PMU_EVENT_SUFFIX, /* suffix of pre-suf style event */
+};
+
+struct kernel_pmu_event_symbol {
+ char symbol[KERNEL_PMU_EVENT_MAX];
+ enum kernel_pmu_event_type type;
+};
+
enum {
PARSE_EVENTS__TERM_TYPE_NUM,
PARSE_EVENTS__TERM_TYPE_STR,
@@ -95,6 +108,8 @@ int parse_events_add_breakpoint(struct list_head *list, int *idx,
void *ptr, char *type);
int parse_events_add_pmu(struct list_head *list, int *idx,
char *pmu , struct list_head *head_config);
+enum kernel_pmu_event_type
+parse_events_pmu_check(const char *name);
void parse_events__set_leader(char *name, struct list_head *list);
void parse_events_update_lists(struct list_head *list_event,
struct list_head *list_all);
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 7a811eb..16d5c1a 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -10,16 +10,6 @@
#include "parse-events.h"
#include "cpumap.h"

-#define UNIT_MAX_LEN 31 /* max length for event unit name */
-
-struct perf_pmu_alias {
- char *name;
- struct list_head terms;
- struct list_head list;
- char unit[UNIT_MAX_LEN+1];
- double scale;
-};
-
struct perf_pmu_format {
char *name;
int value;
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index c14a543..d9e00d6 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -22,6 +22,16 @@ struct perf_pmu {
struct list_head list;
};

+#define UNIT_MAX_LEN 31 /* max length for event unit name */
+
+struct perf_pmu_alias {
+ char *name;
+ struct list_head terms;
+ struct list_head list;
+ char unit[UNIT_MAX_LEN+1];
+ 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);
--
1.8.3.2

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