[tip:perfcounters/core] perf_counter: Add PERF_SAMPLE_PERIOD

tip-bot for Peter Zijlstra
2009-06-05T16:58:39Z

Commit-ID: 689802b2d0536e72281dc959ab9cb34fb3c304cf
Gitweb: http://git.kernel.org/tip/689802b2d0536e72281dc959ab9cb34fb3c304cf
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Fri, 5 Jun 2009 15:05:43 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 5 Jun 2009 18:07:47 +0200

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>

---
include/linux/perf_counter.h | 2 ++
kernel/perf_counter.c | 10 ++++++++++
2 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 9cea32a..6bc2500 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -106,6 +106,7 @@ enum perf_counter_sample_format {
PERF_SAMPLE_CALLCHAIN = 1U << 5,
PERF_SAMPLE_ID = 1U << 6,
PERF_SAMPLE_CPU = 1U << 7,
+ PERF_SAMPLE_PERIOD = 1U << 8,
};

/*
@@ -260,6 +261,7 @@ enum perf_event_type {
* struct {
* struct perf_event_header header;
* u64 time;
+ * u64 id;
* u64 sample_period;
* };
*/
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index e75b91a..f839066 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,
};