[PATCH 07/57] perf tools: Add cpu_map__empty_new function

[Jiri Olsa <jolsa@kernel.org>]

Adding cpu_map__empty_new interface to create empty cpumap
with given size. The cpumap entries are initialized with -1.

It'll be used for caching cpu_map in following patches.

Link: http://lkml.kernel.org/n/tip-2q9tmp3shdscmtiv6h8afhvd@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/cpumap.c | 17 +++++++++++++++++
 tools/perf/util/cpumap.h |  1 +
 2 files changed, 18 insertions(+)

diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index c51c29fd0732..94d30c8d7255 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -203,6 +203,23 @@ struct cpu_map *cpu_map__dummy_new(void)
 	return cpus;
 }
 
+struct cpu_map *cpu_map__empty_new(int nr)
+{
+	struct cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int) * nr);
+
+	if (cpus != NULL) {
+		int i;
+
+		cpus->nr = nr;
+		for (i = 0; i < nr; i++)
+			cpus->map[i] = -1;
+
+		atomic_set(&cpus->refcnt, 1);
+	}
+
+	return cpus;
+}
+
 static void cpu_map__delete(struct cpu_map *map)
 {
 	if (map) {
diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
index 8982d538da83..91fd5d1a4cdc 100644
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -15,6 +15,7 @@ struct cpu_map {
 };
 
 struct cpu_map *cpu_map__new(const char *cpu_list);
+struct cpu_map *cpu_map__empty_new(int nr);
 struct cpu_map *cpu_map__dummy_new(void);
 struct cpu_map *cpu_map__read(FILE *file);
 size_t cpu_map__fprintf(struct cpu_map *map, FILE *fp);
-- 
2.4.3