perf_counter: Add PERF_SAMPLE_PERIOD

In order to allow easy tracking of the period, also provide means of
adding it to the sample data.

Signed-off-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, 10 insertions, 0 deletions

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index e75b91a76a58..f8390668c391 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -2404,6 +2404,11 @@ static void perf_counter_output(struct perf_counter *counter,
                 cpu_entry.cpu = raw_smp_processor_id();
         }
 
+        if (sample_type & PERF_SAMPLE_PERIOD) {
+                header.type |= PERF_SAMPLE_PERIOD;
+                header.size += sizeof(u64);
+        }
+
         if (sample_type & PERF_SAMPLE_GROUP) {
                 header.type |= PERF_SAMPLE_GROUP;
                 header.size += sizeof(u64) +
@@ -2445,6 +2450,9 @@ static void perf_counter_output(struct perf_counter *counter,
         if (sample_type & PERF_SAMPLE_CPU)
                 perf_output_put(&handle, cpu_entry);
 
+        if (sample_type & PERF_SAMPLE_PERIOD)
+                perf_output_put(&handle, counter->hw.sample_period);
+
         /*
          * XXX PERF_SAMPLE_GROUP vs inherited counters seems difficult.
          */
@@ -2835,6 +2843,7 @@ static void perf_log_period(struct perf_counter *counter, u64 period)
         struct {
                 struct perf_event_header        header;
                 u64                             time;
+                u64                             id;
                 u64                             period;
         } freq_event = {
                 .header = {
@@ -2843,6 +2852,7 @@ static void perf_log_period(struct perf_counter *counter, u64 period)
                         .size = sizeof(freq_event),
                 },
                 .time = sched_clock(),
+                .id = counter->id,
                 .period = period,
         };