perf_counter tools: Sample and display frequency adjustment changes

To allow the debugging of frequency-adjusting counters, sample
those adjustments and display them in perf report -D.

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 33 insertions, 6 deletions

diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index 5af105c280b5..242e09ff3658 100644
--- a/Documentation/perf_counter/builtin-report.c
+++ b/Documentation/perf_counter/builtin-report.c
@@ -69,12 +69,20 @@ struct fork_event {
         __u32 pid, ppid;
 };
 
-typedef union event_union {
+struct period_event {
         struct perf_event_header header;
-        struct ip_event ip;
-        struct mmap_event mmap;
-        struct comm_event comm;
-        struct fork_event fork;
+        __u64 time;
+        __u64 id;
+        __u64 sample_period;
+};
+
+typedef union event_union {
+        struct perf_event_header        header;
+        struct ip_event                 ip;
+        struct mmap_event               mmap;
+        struct comm_event               comm;
+        struct fork_event               fork;
+        struct period_event             period;
 } event_t;
 
 static LIST_HEAD(dsos);
@@ -1053,6 +1061,19 @@ process_fork_event(event_t *event, unsigned long offset, unsigned long head)
 }
 
 static int
+process_period_event(event_t *event, unsigned long offset, unsigned long head)
+{
+        dprintf("%p [%p]: PERF_EVENT_PERIOD: time:%Ld, id:%Ld: period:%Ld\n",
+                (void *)(offset + head),
+                (void *)(long)(event->header.size),
+                event->period.time,
+                event->period.id,
+                event->period.sample_period);
+
+        return 0;
+}
+
+static int
 process_event(event_t *event, unsigned long offset, unsigned long head)
 {
         if (event->header.misc & PERF_EVENT_MISC_OVERFLOW)
@@ -1068,11 +1089,12 @@ process_event(event_t *event, unsigned long offset, unsigned long head)
         case PERF_EVENT_FORK:
                 return process_fork_event(event, offset, head);
 
+        case PERF_EVENT_PERIOD:
+                return process_period_event(event, offset, head);
         /*
          * We dont process them right now but they are fine:
          */
 
-        case PERF_EVENT_PERIOD:
         case PERF_EVENT_THROTTLE:
         case PERF_EVENT_UNTHROTTLE:
                 return 0;
@@ -1157,6 +1179,11 @@ more:
 
         size = event->header.size;
 
+        dprintf("%p [%p]: event: %d\n",
+                        (void *)(offset + head),
+                        (void *)(long)event->header.size,
+                        event->header.type);
+
         if (!size || process_event(event, offset, head) < 0) {
 
                 dprintf("%p [%p]: skipping unknown header type: %d\n",