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

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.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0a3d23a2
...@@ -106,6 +106,7 @@ struct perf_kvm_stat { ...@@ -106,6 +106,7 @@ struct perf_kvm_stat {
u64 total_time; u64 total_time;
u64 total_count; u64 total_count;
u64 lost_events; u64 lost_events;
u64 duration;
const char *pid_str; const char *pid_str;
struct intlist *pid_list; struct intlist *pid_list;
...@@ -473,7 +474,7 @@ static bool update_kvm_event(struct kvm_event *event, int vcpu_id, ...@@ -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, static bool handle_end_event(struct perf_kvm_stat *kvm,
struct vcpu_event_record *vcpu_record, struct vcpu_event_record *vcpu_record,
struct event_key *key, struct event_key *key,
u64 timestamp) struct perf_sample *sample)
{ {
struct kvm_event *event; struct kvm_event *event;
u64 time_begin, time_diff; u64 time_begin, time_diff;
...@@ -510,12 +511,24 @@ static bool handle_end_event(struct perf_kvm_stat *kvm, ...@@ -510,12 +511,24 @@ static bool handle_end_event(struct perf_kvm_stat *kvm,
vcpu_record->start_time = 0; vcpu_record->start_time = 0;
/* seems to happen once in a while during live mode */ /* 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"); pr_debug("End time before begin time; skipping event.\n");
return true; 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); return update_kvm_event(event, vcpu, time_diff);
} }
...@@ -562,7 +575,7 @@ static bool handle_kvm_event(struct perf_kvm_stat *kvm, ...@@ -562,7 +575,7 @@ static bool handle_kvm_event(struct perf_kvm_stat *kvm,
return handle_begin_event(kvm, vcpu_record, &key, sample->time); return handle_begin_event(kvm, vcpu_record, &key, sample->time);
if (kvm->events_ops->is_end_event(evsel, sample, &key)) 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; return true;
} }
...@@ -1429,6 +1442,8 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, ...@@ -1429,6 +1442,8 @@ static int kvm_events_live(struct perf_kvm_stat *kvm,
OPT_STRING('k', "key", &kvm->sort_key, "sort-key", OPT_STRING('k', "key", &kvm->sort_key, "sort-key",
"key for sorting: sample(sort by samples number)" "key for sorting: sample(sort by samples number)"
" time (sort by avg time)"), " time (sort by avg time)"),
OPT_U64(0, "duration", &kvm->duration,
"show events other than HALT that take longer than duration usecs"),
OPT_END() OPT_END()
}; };
const char * const live_usage[] = { const char * const live_usage[] = {
...@@ -1467,6 +1482,8 @@ static int kvm_events_live(struct perf_kvm_stat *kvm, ...@@ -1467,6 +1482,8 @@ static int kvm_events_live(struct perf_kvm_stat *kvm,
usage_with_options(live_usage, live_options); usage_with_options(live_usage, live_options);
} }
kvm->duration *= NSEC_PER_USEC; /* convert usec to nsec */
/* /*
* target related setups * target related setups
*/ */
......
...@@ -125,6 +125,9 @@ ...@@ -125,6 +125,9 @@
#ifndef NSEC_PER_SEC #ifndef NSEC_PER_SEC
# define NSEC_PER_SEC 1000000000ULL # define NSEC_PER_SEC 1000000000ULL
#endif #endif
#ifndef NSEC_PER_USEC
# define NSEC_PER_USEC 1000ULL
#endif
static inline unsigned long long rdclock(void) static inline unsigned long long rdclock(void)
{ {
......
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