[PATCH 2/3] perf tools: Add perf_env__numa_node function

[Jiri Olsa]

To speed up cpu to node lookup, adding perf_env__numa_node
function, that creates cpu array on the first lookup, that
holds numa nodes for each stored cpu.

Link: http://lkml.kernel.org/n/tip-qqwxklhissf3yjyuaszh6480@xxxxxxxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
 tools/perf/util/env.c | 40 ++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/env.h |  6 ++++++
 2 files changed, 46 insertions(+)

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 3baca06786fb..ee53e89a9535 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -179,6 +179,7 @@ void perf_env__exit(struct perf_env *env)
 	zfree(&env->sibling_threads);
 	zfree(&env->pmu_mappings);
 	zfree(&env->cpu);
+	zfree(&env->numa_map);
 
 	for (i = 0; i < env->nr_numa_nodes; i++)
 		perf_cpu_map__put(env->numa_nodes[i].map);
@@ -338,3 +339,42 @@ const char *perf_env__arch(struct perf_env *env)
 
 	return normalize_arch(arch_name);
 }
+
+
+int perf_env__numa_node(struct perf_env *env, int cpu)
+{
+	if (!env->nr_numa_map) {
+		struct numa_node *nn;
+		int i, nr = 0;
+
+		for (i = 0; i < env->nr_numa_nodes; i++) {
+			nn = &env->numa_nodes[i];
+			nr = max(nr, perf_cpu_map__max(nn->map));
+		}
+
+		nr++;
+
+		/*
+		 * We initialize the numa_map array to prepare
+		 * it for missing cpus, which return node -1.
+		 */
+		env->numa_map = malloc(nr * sizeof(int));
+		if (!env->numa_map)
+			return -1;
+
+		for (i = 0; i < nr; i++)
+			env->numa_map[i] = -1;
+
+		env->nr_numa_map = nr;
+
+		for (i = 0; i < env->nr_numa_nodes; i++) {
+			int tmp, j;
+
+			nn = &env->numa_nodes[i];
+			perf_cpu_map__for_each_cpu(j, tmp, nn->map)
+				env->numa_map[j] = i;
+		}
+	}
+
+	return cpu >= 0 && cpu < env->nr_numa_map ? env->numa_map[cpu] : -1;
+}
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index d8e083d42610..777008f8007a 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -86,6 +86,10 @@ struct perf_env {
 		struct rb_root		btfs;
 		u32			btfs_cnt;
 	} bpf_progs;
+
+	/* For fast cpu to numa node lookup via perf_env__numa_node */
+	int			*numa_map;
+	int			 nr_numa_map;
 };
 
 enum perf_compress_type {
@@ -118,4 +122,6 @@ struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
 							__u32 prog_id);
 void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node);
 struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id);
+
+int perf_env__numa_node(struct perf_env *env, int cpu);
 #endif /* __PERF_ENV_H */
-- 
2.21.0