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@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1412694532-23391-3-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 141 insertions, 10 deletions

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index c5642e6748b2..c659a3ca1283 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 df094b4ed5ed..db2cf78ff0f3 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 93a41ca96b8e..e243ad962a4d 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c