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]>
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index deaee42..a5698ad 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -347,6 +347,7 @@
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 @@
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
index 0b18cb9..9a0e31e 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -47,6 +47,7 @@
struct perf_event_header header;
__u64 ip;
__u32 pid, tid;
+ __u64 period;
};
struct mmap_event {
@@ -943,12 +944,13 @@
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);
