perf_counter tools: Small frequency related fixes

Create the counter in a disabled state and only enable it after we mmap() the buffer, this allows us to see the first few samples (and observe the frequency ramp). Furthermore, print the period in the verbose report. Signed-off-by: Peter Zijlstra <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <[email protected]>
akeromi · Jun 10, 2009 · 4502d77 · 4502d77
1 parent bd2b5b1
commit 4502d77
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 2 deletions.
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
@@ -347,6 +347,7 @@ static void create_counter(int counter, int cpu, pid_t pid)
 	attr->mmap		= track;
 	attr->comm		= track;
 	attr->inherit		= (cpu < 0) && inherit;
+	attr->disabled		= 1;
 
 	track = 0; /* only the first counter needs these */
 
@@ -402,6 +403,8 @@ static void create_counter(int counter, int cpu, pid_t pid)
 		error("failed to mmap with %d (%s)\n", errno, strerror(errno));
 		exit(-1);
 	}
+
+	ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
 }
 
 static void open_counters(int cpu, pid_t pid)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
@@ -47,6 +47,7 @@ struct ip_event {
 	struct perf_event_header header;
 	__u64 ip;
 	__u32 pid, tid;
+	__u64 period;
 };
 
 struct mmap_event {
@@ -943,12 +944,13 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
 	uint64_t ip = event->ip.ip;
 	struct map *map = NULL;
 
-	dprintf("%p [%p]: PERF_EVENT (IP, %d): %d: %p\n",
+	dprintf("%p [%p]: PERF_EVENT (IP, %d): %d: %p period: %Ld\n",
 		(void *)(offset + head),
 		(void *)(long)(event->header.size),
 		event->header.misc,
 		event->ip.pid,
-		(void *)(long)ip);
+		(void *)(long)ip,
+		(long long)event->ip.period);
 
 	dprintf(" ... thread: %s:%d\n", thread->comm, thread->pid);