[PATCH v4 12/16] perf kvm: Polish sorting key

[Leo Yan <leo.yan@linaro.org>]

Since histograms supports sorting, the tool doesn't need to maintain the
mapping between the sorting keys and the corresponding comparison
callbacks, therefore, this patch removes structure kvm_event_key.

But we still need to validate the sorting key, this patch uses an array
for sorting keys and renames function select_key() to is_valid_key()
to validate the sorting key passed by user.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 tools/perf/builtin-kvm.c   | 29 ++++++++++-------------------
 tools/perf/util/kvm-stat.h |  8 --------
 2 files changed, 10 insertions(+), 27 deletions(-)

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index ba3134613bcb..1e9338855239 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -76,15 +76,6 @@ COMPARE_EVENT_KEY(min, stats.min);
 COMPARE_EVENT_KEY(count, stats.n);
 COMPARE_EVENT_KEY(mean, stats.mean);
 
-#define DEF_SORT_NAME_KEY(name, compare_key)				\
-	{ #name, cmp_event_ ## compare_key }
-
-static struct kvm_event_key keys[] = {
-	DEF_SORT_NAME_KEY(sample, count),
-	DEF_SORT_NAME_KEY(time, mean),
-	{ NULL, NULL }
-};
-
 struct kvm_hists {
 	struct hists		hists;
 	struct perf_hpp_list	list;
@@ -757,18 +748,18 @@ static bool handle_kvm_event(struct perf_kvm_stat *kvm,
 	return true;
 }
 
-static bool select_key(struct perf_kvm_stat *kvm)
+static bool is_valid_key(struct perf_kvm_stat *kvm)
 {
-	int i;
+	static const char *key_array[] = {
+		"ev_name", "sample", "time", "max_t", "min_t", "mean_t",
+	};
+	unsigned int i;
 
-	for (i = 0; keys[i].name; i++) {
-		if (!strcmp(keys[i].name, kvm->sort_key)) {
-			kvm->compare = keys[i].key;
+	for (i = 0; i < ARRAY_SIZE(key_array); i++)
+		if (!strcmp(key_array[i], kvm->sort_key))
 			return true;
-		}
-	}
 
-	pr_err("Unknown compare key:%s\n", kvm->sort_key);
+	pr_err("Unsupported sort key: %s\n", kvm->sort_key);
 	return false;
 }
 
@@ -1198,7 +1189,7 @@ static int kvm_events_live_report(struct perf_kvm_stat *kvm)
 		return ret;
 
 	if (!verify_vcpu(kvm->trace_vcpu) ||
-	    !select_key(kvm) ||
+	    !is_valid_key(kvm) ||
 	    !register_kvm_events_ops(kvm)) {
 		goto out;
 	}
@@ -1393,7 +1384,7 @@ static int kvm_events_report_vcpu(struct perf_kvm_stat *kvm)
 	if (!verify_vcpu(vcpu))
 		goto exit;
 
-	if (!select_key(kvm))
+	if (!is_valid_key(kvm))
 		goto exit;
 
 	if (!register_kvm_events_ops(kvm))
diff --git a/tools/perf/util/kvm-stat.h b/tools/perf/util/kvm-stat.h
index 4385be769eee..35d03894fac3 100644
--- a/tools/perf/util/kvm-stat.h
+++ b/tools/perf/util/kvm-stat.h
@@ -49,13 +49,6 @@ struct kvm_event {
 	struct hist_entry he;
 };
 
-typedef int (*key_cmp_fun)(struct kvm_event*, struct kvm_event*, int);
-
-struct kvm_event_key {
-	const char *name;
-	key_cmp_fun key;
-};
-
 struct child_event_ops {
 	void (*get_key)(struct evsel *evsel,
 			struct perf_sample *sample,
@@ -98,7 +91,6 @@ struct perf_kvm_stat {
 	const char *exit_reasons_isa;
 
 	struct kvm_events_ops *events_ops;
-	key_cmp_fun compare;
 
 	u64 total_time;
 	u64 total_count;
-- 
2.34.1