[PATCH V2 4/6] perf,tools: check and re-organize evsel cpu maps

[Kan Liang <kan.liang@intel.com>]

From: Kan Liang <kan.liang@intel.com>

"-C" can be used to set cpu list. The cpu list may be incompatible with
event's cpumask. This patch discard the incompatible cpu. Only available
cpu can be stored in evsel->cpus->map.
If there is no cpu from cpu list compatible with event's cpumask. It
will error out.

Signed-off-by: Kan Liang <kan.liang@intel.com>
---
 tools/perf/builtin-top.c |  6 ++--
 tools/perf/util/evlist.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 1cb3436..5aba1b2 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1220,9 +1220,6 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (target__none(target))
 		target->system_wide = true;
 
-	if (perf_evlist__create_maps(top.evlist, target) < 0)
-		usage_with_options(top_usage, options);
-
 	if (!top.evlist->nr_entries &&
 	    perf_evlist__add_default(top.evlist) < 0) {
 		ui__error("Not enough memory for event selector list\n");
@@ -1231,6 +1228,9 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 
 	symbol_conf.nr_events = top.evlist->nr_entries;
 
+	if (perf_evlist__create_maps(top.evlist, target) < 0)
+		usage_with_options(top_usage, options);
+
 	if (top.delay_secs < 1)
 		top.delay_secs = 1;
 
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index a065150..16319b4 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1068,6 +1068,74 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
 	return perf_evlist__mmap_per_cpu(evlist, &mp);
 }
 
+static int cmp_ids(const void *a, const void *b)
+{
+	return *(int *)a - *(int *)b;
+}
+
+/*
+ * Check evsel cpu map according to pmu cpumask and input
+ * Only available cpu can be stored in evsel->cpus->map.
+ */
+static int perf_evlist__check_evsel_cpus(struct perf_evlist *evlist)
+{
+	const struct cpu_map *cpus = evlist->cpus;
+	const int ncpus = cpu_map__nr(evlist->cpus);
+	struct perf_evsel *evsel;
+	int i, j, cpu_nr, tmp;
+
+	/* ensure we process id in increasing order */
+	qsort(evlist->cpus->map, evlist->cpus->nr, sizeof(int), cmp_ids);
+
+	evlist__for_each(evlist, evsel) {
+		if (evsel->cpus == cpus)
+			continue;
+
+		cpu_nr = 0;
+		j = 0;
+		for (i = 0; i < cpu_map__nr(evsel->cpus);)  {
+
+			if (j >= ncpus) {
+				evsel->cpus->map[i++] = -1;
+				continue;
+			}
+			for (; j < ncpus; j++) {
+				if (cpus->map[j] < evsel->cpus->map[i])
+					continue;
+				if (cpus->map[j] == evsel->cpus->map[i]) {
+					cpu_nr++;
+					j++;
+					i++;
+				} else
+					evsel->cpus->map[i++] = -1;
+				break;
+			}
+		}
+
+		if (cpu_nr == cpu_map__nr(evsel->cpus))
+			continue;
+		if (cpu_nr == 0) {
+			perror("failed to create CPUs map, please check cpumask");
+			return -1;
+		}
+
+		tmp = 0;
+		for (i = 0; i < cpu_nr; i++) {
+			if (evsel->cpus->map[i] == -1) {
+				while (evsel->cpus->map[tmp] == -1) {
+					tmp++;
+					BUG_ON(tmp >= cpu_map__nr(evsel->cpus));
+				}
+				evsel->cpus->map[i] = evsel->cpus->map[tmp];
+				evsel->cpus->map[tmp] = -1;
+			}
+			tmp++;
+		}
+		evsel->cpus->nr = cpu_nr;
+	}
+	return 0;
+}
+
 int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
 {
 	struct cpu_map *cpus;
@@ -1088,6 +1156,10 @@ int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
 
 	perf_evlist__set_cpus(evlist, cpus);
 
+	if (target->cpu_list &&
+	   (perf_evlist__check_evsel_cpus(evlist) < 0))
+		goto out_delete_threads;
+
 	return 0;
 
 out_delete_threads:
-- 
1.8.3.1