perf_counter tools: Handle lost events
Make use of the new ->data_tail mechanism to tell kernel-space
about user-space draining the data stream. Emit lost events
(and display them) if they happen.
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>
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 9a3805f..fe66895 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -83,6 +83,12 @@
__u64 sample_period;
};
+struct lost_event {
+ struct perf_event_header header;
+ __u64 id;
+ __u64 lost;
+};
+
typedef union event_union {
struct perf_event_header header;
struct ip_event ip;
@@ -90,6 +96,7 @@
struct comm_event comm;
struct fork_event fork;
struct period_event period;
+ struct lost_event lost;
} event_t;
static LIST_HEAD(dsos);
@@ -1068,7 +1075,8 @@
total_mmap = 0,
total_comm = 0,
total_fork = 0,
- total_unknown = 0;
+ total_unknown = 0,
+ total_lost = 0;
static int validate_chain(struct perf_callchain_entry *chain, event_t *event)
{
@@ -1260,6 +1268,20 @@
return 0;
}
+static int
+process_lost_event(event_t *event, unsigned long offset, unsigned long head)
+{
+ dprintf("%p [%p]: PERF_EVENT_LOST: id:%Ld: lost:%Ld\n",
+ (void *)(offset + head),
+ (void *)(long)(event->header.size),
+ event->lost.id,
+ event->lost.lost);
+
+ total_lost += event->lost.lost;
+
+ return 0;
+}
+
static void trace_event(event_t *event)
{
unsigned char *raw_event = (void *)event;
@@ -1316,6 +1338,10 @@
case PERF_EVENT_PERIOD:
return process_period_event(event, offset, head);
+
+ case PERF_EVENT_LOST:
+ return process_lost_event(event, offset, head);
+
/*
* We dont process them right now but they are fine:
*/
@@ -1444,6 +1470,7 @@
dprintf(" mmap events: %10ld\n", total_mmap);
dprintf(" comm events: %10ld\n", total_comm);
dprintf(" fork events: %10ld\n", total_fork);
+ dprintf(" lost events: %10ld\n", total_lost);
dprintf(" unknown events: %10ld\n", total_unknown);
if (dump_trace)
