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Commit 70f7b4a7 authored by David Ahern's avatar David Ahern Committed by Arnaldo Carvalho de Melo
Browse files

perf kvm: Option to print events that exceed a duration 



This is useful to spot high latency blips. It is normal for HLT reasons
to have long exit times, so strip those from the duration check.

v2: changed threshold to duration per acme's request

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1375926999-75129-1-git-send-email-dsahern@gmail.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0a3d23a2

tools/perf/builtin-kvm.c

+21 −4
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ struct perf_kvm_stat { 
	u64 total_time;

	u64 total_count;

	u64 lost_events;

	u64 duration;



	const char *pid_str;

	struct intlist *pid_list;
@@ -473,7 +474,7 @@ static bool update_kvm_event(struct kvm_event *event, int vcpu_id, 
static bool handle_end_event(struct perf_kvm_stat *kvm,

			     struct vcpu_event_record *vcpu_record,

			     struct event_key *key,

			     u64 timestamp)

			     struct perf_sample *sample)

{

	struct kvm_event *event;

	u64 time_begin, time_diff;
@@ -510,12 +511,24 @@ static bool handle_end_event(struct perf_kvm_stat *kvm, 
	vcpu_record->start_time = 0;



	/* seems to happen once in a while during live mode */

	if (timestamp < time_begin) {

	if (sample->time < time_begin) {

		pr_debug("End time before begin time; skipping event.\n");

		return true;

	}



	time_diff = timestamp - time_begin;

	time_diff = sample->time - time_begin;



	if (kvm->duration && time_diff > kvm->duration) {

		char decode[32];



		kvm->events_ops->decode_key(kvm, &event->key, decode);

		if (strcmp(decode, "HLT")) {

			pr_info("%" PRIu64 " VM %d, vcpu %d: %s event took %" PRIu64 "usec\n",

				 sample->time, sample->pid, vcpu_record->vcpu_id,

				 decode, time_diff/1000);

		}

	}



	return update_kvm_event(event, vcpu, time_diff);

}
@@ -562,7 +575,7 @@ static bool handle_kvm_event(struct perf_kvm_stat *kvm, 
		return handle_begin_event(kvm, vcpu_record, &key, sample->time);



	if (kvm->events_ops->is_end_event(evsel, sample, &key))

		return handle_end_event(kvm, vcpu_record, &key, sample->time);

		return handle_end_event(kvm, vcpu_record, &key, sample);



	return true;

}
@@ -1429,6 +1442,8 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, 
		OPT_STRING('k', "key", &kvm->sort_key, "sort-key",

			"key for sorting: sample(sort by samples number)"

			" time (sort by avg time)"),

		OPT_U64(0, "duration", &kvm->duration,

		    "show events other than HALT that take longer than duration usecs"),

		OPT_END()

	};

	const char * const live_usage[] = {
@@ -1467,6 +1482,8 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, 
			usage_with_options(live_usage, live_options);

	}



	kvm->duration *= NSEC_PER_USEC;   /* convert usec to nsec */



	/*

	 * target related setups

	 */

tools/perf/perf.h

+3 −0
Original line number Diff line number Diff line
@@ -125,6 +125,9 @@ 
#ifndef NSEC_PER_SEC

# define NSEC_PER_SEC			1000000000ULL

#endif

#ifndef NSEC_PER_USEC

# define NSEC_PER_USEC			1000ULL

#endif



static inline unsigned long long rdclock(void)

{