[tip:perf/urgent] perf tools: Parse the pmu event prefix and suffix

From: tip-bot for Kan Liang
Date: Thu Oct 16 2014 - 01:22:54 EST

Commit-ID: dcb4e1022b40d886027500821a592dd8f8ccde8f
Gitweb: http://git.kernel.org/tip/dcb4e1022b40d886027500821a592dd8f8ccde8f
Author: Kan Liang <kan.liang@xxxxxxxxx>
AuthorDate: Tue, 7 Oct 2014 11:08:50 -0400
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 15 Oct 2014 16:05:01 -0300

perf tools: Parse the pmu event prefix and suffix

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.

Note: Currently, the patch only want to handle the PMU event name as
"a-b" and "a". The only exception, "stalled-cycles-frontend" and
"stalled-cycles-fronted", are already hardcoded in lexer.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1412694532-23391-3-git-send-email-kan.liang@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/parse-events.c | 117 +++++++++++++++++++++++++++++++++++++++++
tools/perf/util/parse-events.h | 14 +++++
tools/perf/util/pmu.c | 10 ----
tools/perf/util/pmu.h | 10 ++++
4 files changed, 141 insertions(+), 10 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index c5642e6..c659a3c 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -30,6 +30,15 @@ extern int parse_events_debug;
#endif
int parse_events_parse(void *data, void *scanner);

+static struct perf_pmu_event_symbol *perf_pmu_events_list;
+/*
+ * The variable indicates the number of supported pmu event symbols.
+ * 0 means not initialized and ready to init
+ * -1 means failed to init, don't try anymore
+ * >0 is the number of supported pmu event symbols
+ */
+static int perf_pmu_events_list_num;
+
static struct event_symbol event_symbols_hw[PERF_COUNT_HW_MAX] = {
[PERF_COUNT_HW_CPU_CYCLES] = {
.symbol = "cpu-cycles",
@@ -863,6 +872,113 @@ int parse_events_name(struct list_head *list, char *name)
return 0;
}

+static int
+comp_pmu(const void *p1, const void *p2)
+{
+ struct perf_pmu_event_symbol *pmu1 = (struct perf_pmu_event_symbol *) p1;
+ struct perf_pmu_event_symbol *pmu2 = (struct perf_pmu_event_symbol *) p2;
+
+ return strcmp(pmu1->symbol, pmu2->symbol);
+}
+
+static void perf_pmu__parse_cleanup(void)
+{
+ if (perf_pmu_events_list_num > 0) {
+ struct perf_pmu_event_symbol *p;
+ int i;
+
+ for (i = 0; i < perf_pmu_events_list_num; i++) {
+ p = perf_pmu_events_list + i;
+ free(p->symbol);
+ }
+ free(perf_pmu_events_list);
+ perf_pmu_events_list = NULL;
+ perf_pmu_events_list_num = 0;
+ }
+}
+
+#define SET_SYMBOL(str, stype) \
+do { \
+ p->symbol = str; \
+ if (!p->symbol) \
+ goto err; \
+ p->type = stype; \
+} while (0)
+
+/*
+ * Read the pmu events list from sysfs
+ * Save it into perf_pmu_events_list
+ */
+static void perf_pmu__parse_init(void)
+{
+
+ struct perf_pmu *pmu = NULL;
+ struct perf_pmu_alias *alias;
+ int len = 0;
+
+ pmu = perf_pmu__find("cpu");
+ if ((pmu == NULL) || list_empty(&pmu->aliases)) {
+ perf_pmu_events_list_num = -1;
+ return;
+ }
+ list_for_each_entry(alias, &pmu->aliases, list) {
+ if (strchr(alias->name, '-'))
+ len++;
+ len++;
+ }
+ perf_pmu_events_list = malloc(sizeof(struct perf_pmu_event_symbol) * len);
+ if (!perf_pmu_events_list)
+ return;
+ perf_pmu_events_list_num = len;
+
+ len = 0;
+ list_for_each_entry(alias, &pmu->aliases, list) {
+ struct perf_pmu_event_symbol *p = perf_pmu_events_list + len;
+ char *tmp = strchr(alias->name, '-');
+
+ if (tmp != NULL) {
+ SET_SYMBOL(strndup(alias->name, tmp - alias->name),
+ PMU_EVENT_SYMBOL_PREFIX);
+ p++;
+ SET_SYMBOL(strdup(++tmp), PMU_EVENT_SYMBOL_SUFFIX);
+ len += 2;
+ } else {
+ SET_SYMBOL(strdup(alias->name), PMU_EVENT_SYMBOL);
+ len++;
+ }
+ }
+ qsort(perf_pmu_events_list, len,
+ sizeof(struct perf_pmu_event_symbol), comp_pmu);
+
+ return;
+err:
+ perf_pmu__parse_cleanup();
+}
+
+enum perf_pmu_event_symbol_type
+perf_pmu__parse_check(const char *name)
+{
+ struct perf_pmu_event_symbol p, *r;
+
+ /* scan kernel pmu events from sysfs if needed */
+ if (perf_pmu_events_list_num == 0)
+ perf_pmu__parse_init();
+ /*
+ * 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 ((perf_pmu_events_list_num <= 0) || !strcmp(name, "cpu"))
+ return PMU_EVENT_SYMBOL_ERR;
+
+ p.symbol = strdup(name);
+ r = bsearch(&p, perf_pmu_events_list,
+ (size_t) perf_pmu_events_list_num,
+ sizeof(struct perf_pmu_event_symbol), comp_pmu);
+ free(p.symbol);
+ return r ? r->type : PMU_EVENT_SYMBOL_ERR;
+}
+
static int parse_events__scanner(const char *str, void *data, int start_token)
{
YY_BUFFER_STATE buffer;
@@ -917,6 +1033,7 @@ int parse_events(struct perf_evlist *evlist, const char *str)
int ret;

ret = parse_events__scanner(str, &data, PE_START_EVENTS);
+ perf_pmu__parse_cleanup();
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..db2cf78 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -35,6 +35,18 @@ extern int parse_filter(const struct option *opt, const char *str, int unset);

#define EVENTS_HELP_MAX (128*1024)

+enum perf_pmu_event_symbol_type {
+ PMU_EVENT_SYMBOL_ERR, /* not a PMU EVENT */
+ PMU_EVENT_SYMBOL, /* normal style PMU event */
+ PMU_EVENT_SYMBOL_PREFIX, /* prefix of pre-suf style event */
+ PMU_EVENT_SYMBOL_SUFFIX, /* suffix of pre-suf style event */
+};
+
+struct perf_pmu_event_symbol {
+ char *symbol;
+ enum perf_pmu_event_symbol_type type;
+};
+
enum {
PARSE_EVENTS__TERM_TYPE_NUM,
PARSE_EVENTS__TERM_TYPE_STR,
@@ -95,6 +107,8 @@ 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 perf_pmu_event_symbol_type
+perf_pmu__parse_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 93a41ca..e243ad9 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -12,16 +12,6 @@
#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; /* HEAD struct parse_events_term -> list */
- struct list_head list; /* ELEM */
- 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 fe90a01..fe9dfbe 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -30,6 +30,16 @@ struct perf_pmu_info {
double scale;
};

+#define UNIT_MAX_LEN 31 /* max length for event unit name */
+
+struct perf_pmu_alias {
+ char *name;
+ struct list_head terms; /* HEAD struct parse_events_term -> list */
+ struct list_head list; /* ELEM */
+ 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);
--
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