perf kvm: Add dimensions for percentages

Add dimensions for count and time percentages, it would be useful for
user to review percentage statistics.

Reviewed-by: James Clark <[e-mail]>
Signed-off-by: Leo Yan <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: John Garry <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-kvm.c

···
 	.width		= 14,
 };
 
+#define PERC_STR(__s, __v)				\
+({							\
+	scnprintf(__s, sizeof(__s), "%.2F%%", __v);	\
+	__s;						\
+})
+
+static double percent(u64 st, u64 tot)
+{
+	return tot ? 100. * (double) st / (double) tot : 0;
+}
+
+#define EV_METRIC_PERCENT(metric)					\
+static int ev_percent_##metric(struct hist_entry *he)			\
+{									\
+	struct kvm_event *event;					\
+	struct perf_kvm_stat *perf_kvm;					\
+									\
+	event = container_of(he, struct kvm_event, he);			\
+	perf_kvm = event->perf_kvm;					\
+									\
+	return percent(get_event_##metric(event, perf_kvm->trace_vcpu),	\
+		       perf_kvm->total_##metric);			\
+}
+
+EV_METRIC_PERCENT(time)
+EV_METRIC_PERCENT(count)
+
+static int ev_entry_time_precent(struct perf_hpp_fmt *fmt,
+				 struct perf_hpp *hpp,
+				 struct hist_entry *he)
+{
+	int width = fmt_width(fmt, hpp, he->hists);
+	double per;
+	char buf[10];
+
+	per = ev_percent_time(he);
+	return scnprintf(hpp->buf, hpp->size, "%*s", width, PERC_STR(buf, per));
+}
+
+static int64_t
+ev_cmp_time_precent(struct perf_hpp_fmt *fmt __maybe_unused,
+		    struct hist_entry *left, struct hist_entry *right)
+{
+	double per_left;
+	double per_right;
+
+	per_left  = ev_percent_time(left);
+	per_right = ev_percent_time(right);
+
+	return per_left - per_right;
+}
+
+static struct kvm_dimension dim_time_percent = {
+	.header		= "Time%",
+	.name		= "percent_time",
+	.cmp		= ev_cmp_time_precent,
+	.entry		= ev_entry_time_precent,
+	.width		= 12,
+};
+
+static int ev_entry_count_precent(struct perf_hpp_fmt *fmt,
+				  struct perf_hpp *hpp,
+				  struct hist_entry *he)
+{
+	int width = fmt_width(fmt, hpp, he->hists);
+	double per;
+	char buf[10];
+
+	per = ev_percent_count(he);
+	return scnprintf(hpp->buf, hpp->size, "%*s", width, PERC_STR(buf, per));
+}
+
+static int64_t
+ev_cmp_count_precent(struct perf_hpp_fmt *fmt __maybe_unused,
+		     struct hist_entry *left, struct hist_entry *right)
+{
+	double per_left;
+	double per_right;
+
+	per_left  = ev_percent_count(left);
+	per_right = ev_percent_count(right);
+
+	return per_left - per_right;
+}
+
+static struct kvm_dimension dim_count_percent = {
+	.header		= "Sample%",
+	.name		= "percent_sample",
+	.cmp		= ev_cmp_count_precent,
+	.entry		= ev_entry_count_precent,
+	.width		= 12,
+};
+
 static struct kvm_dimension *dimensions[] = {
 	&dim_event,
 	&dim_time,
+	&dim_time_percent,
 	&dim_count,
+	&dim_count_percent,
 	&dim_max_time,
 	&dim_min_time,
 	&dim_mean_time,
···
 
 static void sort_result(struct perf_kvm_stat *kvm)
 {
-	const char *output_columns = "ev_name,sample,time,max_t,min_t,mean_t";
+	const char *output_columns = "ev_name,sample,percent_sample,"
+				     "time,percent_time,max_t,min_t,mean_t";
 
 	kvm_hists__reinit(output_columns, kvm->sort_key);
 	hists__collapse_resort(&kvm_hists.hists, NULL);