[tip: perf/core] perf env: Add routine to read the env->cpuid from the running machine

[tip-bot2 for Arnaldo Carvalho de Melo]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     f1cedfb82858c8a7ec21e45d0ce7b6e2ce9edea0
Gitweb:        https://git.kernel.org/tip/f1cedfb82858c8a7ec21e45d0ce7b6e2ce9edea0
Author:        Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate:    Mon, 30 Sep 2019 11:50:15 -03:00
Committer:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Mon, 07 Oct 2019 12:22:17 -03:00

perf env: Add routine to read the env->cpuid from the running machine

In 'perf top' we use that cpuid when initializing the per arch
annotation init routines (e.g. x86__annotate_init()) and in that case
(live mode, 'perf top') we need to obtain it from the running machine,
not from a perf.data file header.

Provide a means to do that. Will be used by 'perf top' in a followup
patch.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-h2wb3sx7u7znx6lqfezrh7ca@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/env.c | 16 ++++++++++++++++
 tools/perf/util/env.h |  1 +
 2 files changed, 17 insertions(+)

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 3baca06..2a91a10 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -2,6 +2,7 @@
 #include "cpumap.h"
 #include "debug.h"
 #include "env.h"
+#include "util/header.h"
 #include <linux/ctype.h>
 #include <linux/zalloc.h>
 #include "bpf-event.h"
@@ -256,6 +257,21 @@ int perf_env__read_cpu_topology_map(struct perf_env *env)
 	return 0;
 }
 
+int perf_env__read_cpuid(struct perf_env *env)
+{
+	char cpuid[128];
+	int err = get_cpuid(cpuid, sizeof(cpuid));
+
+	if (err)
+		return err;
+
+	free(env->cpuid);
+	env->cpuid = strdup(cpuid);
+	if (env->cpuid == NULL)
+		return ENOMEM;
+	return 0;
+}
+
 static int perf_env__read_arch(struct perf_env *env)
 {
 	struct utsname uts;
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index db40906..a3059dc 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -104,6 +104,7 @@ void perf_env__exit(struct perf_env *env);
 
 int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[]);
 
+int perf_env__read_cpuid(struct perf_env *env);
 int perf_env__read_cpu_topology_map(struct perf_env *env);
 
 void cpu_cache_level__free(struct cpu_cache_level *cache);