perf timechart: Adjust perf timechart to the new power events

builtin-timechart must only pass -e power:xy events if they are supported by
the running kernel, otherwise try to fetch the old power:power{start,end}
events.

For this I added the tiny helper function:

   int is_valid_tracepoint(const char *event_string)

to parse-events.[hc], which could be more generic as an interface and support
hardware/software/... events, not only tracepoints, but someone else could
extend that if needed...

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
LKML-Reference: <1294073445-14812-4-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 118 insertions, 18 deletions

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index d75084bccdb7..746cf03cb05d 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -32,6 +32,10 @@
 #include "util/session.h"
 #include "util/svghelper.h"
 
+#define SUPPORT_OLD_POWER_EVENTS 1
+#define PWR_EVENT_EXIT -1
+
+
 static char             const *input_name = "perf.data";
 static char             const *output_name = "output.svg";
 
@@ -301,12 +305,21 @@ struct trace_entry {
         int                     lock_depth;
 };
 
-struct power_entry {
+#ifdef SUPPORT_OLD_POWER_EVENTS
+static int use_old_power_events;
+struct power_entry_old {
         struct trace_entry te;
         u64     type;
         u64     value;
         u64     cpu_id;
 };
+#endif
+
+struct power_processor_entry {
+        struct trace_entry te;
+        u32     state;
+        u32     cpu_id;
+};
 
 #define TASK_COMM_LEN 16
 struct wakeup_entry {
@@ -489,29 +502,49 @@ static int process_sample_event(event_t *event __used,
         te = (void *)sample->raw_data;
         if (session->sample_type & PERF_SAMPLE_RAW && sample->raw_size > 0) {
                 char *event_str;
-                struct power_entry *pe;
-
-                pe = (void *)te;
-
+#ifdef SUPPORT_OLD_POWER_EVENTS
+                struct power_entry_old *peo;
+                peo = (void *)te;
+#endif
                 event_str = perf_header__find_event(te->type);
 
                 if (!event_str)
                         return 0;
 
-                if (strcmp(event_str, "power:power_start") == 0)
-                        c_state_start(pe->cpu_id, sample->time, pe->value);
-
-                if (strcmp(event_str, "power:power_end") == 0)
-                        c_state_end(pe->cpu_id, sample->time);
-
-                if (strcmp(event_str, "power:power_frequency") == 0)
-                        p_state_change(pe->cpu_id, sample->time, pe->value);
+                if (strcmp(event_str, "power:cpu_idle") == 0) {
+                        struct power_processor_entry *ppe = (void *)te;
+                        if (ppe->state == (u32)PWR_EVENT_EXIT)
+                                c_state_end(ppe->cpu_id, sample->time);
+                        else
+                                c_state_start(ppe->cpu_id, sample->time,
+                                              ppe->state);
+                }
+                else if (strcmp(event_str, "power:cpu_frequency") == 0) {
+                        struct power_processor_entry *ppe = (void *)te;
+                        p_state_change(ppe->cpu_id, sample->time, ppe->state);
+                }
 
-                if (strcmp(event_str, "sched:sched_wakeup") == 0)
+                else if (strcmp(event_str, "sched:sched_wakeup") == 0)
                         sched_wakeup(sample->cpu, sample->time, sample->pid, te);
 
-                if (strcmp(event_str, "sched:sched_switch") == 0)
+                else if (strcmp(event_str, "sched:sched_switch") == 0)
                         sched_switch(sample->cpu, sample->time, te);
+
+#ifdef SUPPORT_OLD_POWER_EVENTS
+                if (use_old_power_events) {
+                        if (strcmp(event_str, "power:power_start") == 0)
+                                c_state_start(peo->cpu_id, sample->time,
+                                              peo->value);
+
+                        else if (strcmp(event_str, "power:power_end") == 0)
+                                c_state_end(sample->cpu, sample->time);
+
+                        else if (strcmp(event_str,
+                                        "power:power_frequency") == 0)
+                                p_state_change(peo->cpu_id, sample->time,
+                                               peo->value);
+                }
+#endif
         }
         return 0;
 }
@@ -969,7 +1002,8 @@ static const char * const timechart_usage[] = {
         NULL
 };
 
-static const char *record_args[] = {
+#ifdef SUPPORT_OLD_POWER_EVENTS
+static const char * const record_old_args[] = {
         "record",
         "-a",
         "-R",
@@ -981,19 +1015,43 @@ static const char *record_args[] = {
         "-e", "sched:sched_wakeup",
         "-e", "sched:sched_switch",
 };
+#endif
+
+static const char * const record_new_args[] = {
+        "record",
+        "-a",
+        "-R",
+        "-f",
+        "-c", "1",
+        "-e", "power:cpu_frequency",
+        "-e", "power:cpu_idle",
+        "-e", "sched:sched_wakeup",
+        "-e", "sched:sched_switch",
+};
 
 static int __cmd_record(int argc, const char **argv)
 {
         unsigned int rec_argc, i, j;
         const char **rec_argv;
+        const char * const *record_args = record_new_args;
+        unsigned int record_elems = ARRAY_SIZE(record_new_args);
+
+#ifdef SUPPORT_OLD_POWER_EVENTS
+        if (!is_valid_tracepoint("power:cpu_idle") &&
+            is_valid_tracepoint("power:power_start")) {
+                use_old_power_events = 1;
+                record_args = record_old_args;
+                record_elems = ARRAY_SIZE(record_old_args);
+        }
+#endif
 
-        rec_argc = ARRAY_SIZE(record_args) + argc - 1;
+        rec_argc = record_elems + argc - 1;
         rec_argv = calloc(rec_argc + 1, sizeof(char *));
 
         if (rec_argv == NULL)
                 return -ENOMEM;
 
-        for (i = 0; i < ARRAY_SIZE(record_args); i++)
+        for (i = 0; i < record_elems; i++)
                 rec_argv[i] = strdup(record_args[i]);
 
         for (j = 1; j < (unsigned int)argc; j++, i++)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 3a142e90d609..649083f27e08 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -913,6 +913,47 @@ static void print_tracepoint_events(void)
 }
 
 /*
+ * Check whether event is in <debugfs_mount_point>/tracing/events
+ */
+
+int is_valid_tracepoint(const char *event_string)
+{
+        DIR *sys_dir, *evt_dir;
+        struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
+        char evt_path[MAXPATHLEN];
+        char dir_path[MAXPATHLEN];
+
+        if (debugfs_valid_mountpoint(debugfs_path))
+                return 0;
+
+        sys_dir = opendir(debugfs_path);
+        if (!sys_dir)
+                return 0;
+
+        for_each_subsystem(sys_dir, sys_dirent, sys_next) {
+
+                snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,
+                         sys_dirent.d_name);
+                evt_dir = opendir(dir_path);
+                if (!evt_dir)
+                        continue;
+
+                for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
+                        snprintf(evt_path, MAXPATHLEN, "%s:%s",
+                                 sys_dirent.d_name, evt_dirent.d_name);
+                        if (!strcmp(evt_path, event_string)) {
+                                closedir(evt_dir);
+                                closedir(sys_dir);
+                                return 1;
+                        }
+                }
+                closedir(evt_dir);
+        }
+        closedir(sys_dir);
+        return 0;
+}
+
+/*
  * Print the help text for the event symbols:
  */
 void print_events(void)
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 0a0abc1d10eb..1c9043ccd173 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -36,6 +36,7 @@ extern int parse_filter(const struct option *opt, const char *str, int unset);
 #define EVENTS_HELP_MAX (128*1024)
 
 extern void print_events(void);
+extern int is_valid_tracepoint(const char *event_string);
 
 extern char debugfs_path[];
 extern int valid_debugfs_mount(const char *debugfs);