Re: [PATCH/RFC] KVM: perf/stat: Properly show submicrosecond times

From: David Ahern
Date: Thu Jul 31 2014 - 10:24:10 EST


On 7/31/14, 5:13 AM, Christian Borntraeger wrote:
For lots of exits the min time (and sometimes max) is 0 or 1. Lets
increase the accurancy similar to what the average field alread does.

Seems reasonable to me.

Acked-by: David Ahern <dsahern@xxxxxxxxx>



Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
tools/perf/builtin-kvm.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 43367eb..fe92dfd 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -592,8 +592,8 @@ static void print_result(struct perf_kvm_stat *kvm)
pr_info("%9s ", "Samples%");

pr_info("%9s ", "Time%");
- pr_info("%10s ", "Min Time");
- pr_info("%10s ", "Max Time");
+ pr_info("%11s ", "Min Time");
+ pr_info("%11s ", "Max Time");
pr_info("%16s ", "Avg time");
pr_info("\n\n");

@@ -610,8 +610,8 @@ static void print_result(struct perf_kvm_stat *kvm)
pr_info("%10llu ", (unsigned long long)ecount);
pr_info("%8.2f%% ", (double)ecount / kvm->total_count * 100);
pr_info("%8.2f%% ", (double)etime / kvm->total_time * 100);
- pr_info("%8" PRIu64 "us ", min / 1000);
- pr_info("%8" PRIu64 "us ", max / 1000);
+ pr_info("%9.2fus ", (double)min / 1e3);
+ pr_info("%9.2fus ", (double)max / 1e3);
pr_info("%9.2fus ( +-%7.2f%% )", (double)etime / ecount/1e3,
kvm_event_rel_stddev(vcpu, event));
pr_info("\n");


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