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>

diff --git a/Documentation/perf_counter/builtin-record.c b/Documentation/perf_counter/builtin-record.c
index d4ad305..43ddab3 100644 (file)
--- a/Documentation/perf_counter/builtin-record.c
+++ b/Documentation/perf_counter/builtin-record.c
@@ -347,7 +347,7 @@ static void create_counter(int counter, int cpu, pid_t pid)
        memset(&attr, 0, sizeof(attr));
        attr.config             = event_id[counter];
        attr.sample_period      = event_count[counter];
-       attr.sample_type        = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
+       attr.sample_type        = PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_PERIOD;
        attr.freq               = freq;
        attr.mmap               = track;
        attr.comm               = track;

diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index 5af105c..242e09f 100644 (file)
--- 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",