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Subject[PATCH 19/25] perf kvm: Only process events for vcpus of interest
Date
From: David Ahern <dsahern@gmail.com>

Minimizing processing overhead for each sample - which becomes important
for the upcoming live mode when it has to deal with 100+k events per
second.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Dong Hao <haodong@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1349716656-48165-12-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-kvm.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 260abc5..b98095e 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -416,7 +416,10 @@ static double kvm_event_rel_stddev(int vcpu_id, struct kvm_event *event)
static bool update_kvm_event(struct kvm_event *event, int vcpu_id,
u64 time_diff)
{
- kvm_update_event_stats(&event->total, time_diff);
+ if (vcpu_id == -1) {
+ kvm_update_event_stats(&event->total, time_diff);
+ return true;
+ }

if (!kvm_event_expand(event, vcpu_id))
return false;
@@ -432,6 +435,12 @@ static bool handle_end_event(struct perf_kvm *kvm,
{
struct kvm_event *event;
u64 time_begin, time_diff;
+ int vcpu;
+
+ if (kvm->trace_vcpu == -1)
+ vcpu = -1;
+ else
+ vcpu = vcpu_record->vcpu_id;

event = vcpu_record->last_event;
time_begin = vcpu_record->start_time;
@@ -461,7 +470,7 @@ static bool handle_end_event(struct perf_kvm *kvm,
BUG_ON(timestamp < time_begin);

time_diff = timestamp - time_begin;
- return update_kvm_event(event, vcpu_record->vcpu_id, time_diff);
+ return update_kvm_event(event, vcpu, time_diff);
}

static
@@ -498,6 +507,11 @@ static bool handle_kvm_event(struct perf_kvm *kvm,
if (!vcpu_record)
return true;

+ /* only process events for vcpus user cares about */
+ if ((kvm->trace_vcpu != -1) &&
+ (kvm->trace_vcpu != vcpu_record->vcpu_id))
+ return true;
+
if (kvm->events_ops->is_begin_event(evsel, sample, &key))
return handle_begin_event(kvm, vcpu_record, &key, sample->time);

--
1.7.9.2.358.g22243


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