perf build-id: Move disable_buildid_cache() to util/build-id.c

Also move static variable no_buildid_cache and check it in the
perf_session_cache_build_ids().

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pekka Enberg <penberg@iki.fi>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Cc: systemtap@sourceware.org
Link: http://lkml.kernel.org/r/1415368677-3794-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/build-id.c

@@ -18,6 +18,9 @@
 #include "header.h"
 #include "vdso.h"
 
+
+static bool no_buildid_cache;
+
 int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
 			   union perf_event *event,
 			   struct perf_sample *sample,
@@ -251,6 +254,11 @@ int dsos__hit_all(struct perf_session *session)
 	return 0;
 }
 
+void disable_buildid_cache(void)
+{
+	no_buildid_cache = true;
+}
+
 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 			  const char *name, bool is_kallsyms, bool is_vdso)
 {
@@ -404,6 +412,9 @@ int perf_session__cache_build_ids(struct perf_session *session)
 	int ret;
 	char debugdir[PATH_MAX];
 
+	if (no_buildid_cache)
+		return 0;
+
 	snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);
 
 	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)