perf target: Add uses_mmap field

If perf doesn't mmap on event (like perf stat), it should not create
per-task-per-cpu events. So just use a dummy cpu map to create a
per-task event for this case.
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337161549-9870-3-git-send-email-namhyung.kim@lge.com
[ committer note: renamed .need_mmap to .uses_mmap ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

@@ -754,6 +754,9 @@ static struct perf_record record = {
 		.user_freq	     = UINT_MAX,
 		.user_interval	     = ULLONG_MAX,
 		.freq		     = 1000,
+		.target		     = {
+			.uses_mmap   = true,
+		},
 	},
 	.write_mode = WRITE_FORCE,
 	.file_new   = true,

tools/perf/builtin-test.c

@@ -1167,6 +1167,7 @@ static int test__PERF_RECORD(void)
 	struct perf_record_opts opts = {
 		.target = {
 			.uid = UINT_MAX,
+			.uses_mmap = true,
 		},
 		.no_delay   = true,
 		.freq	    = 10,

tools/perf/builtin-top.c

@@ -1162,6 +1162,9 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
 		.freq		     = 1000, /* 1 KHz */
 		.mmap_pages	     = 128,
 		.sym_pcnt_filter     = 5,
+		.target		     = {
+			.uses_mmap   = true,
+		},
 	};
 	char callchain_default_opt[] = "fractal,0.5,callee";
 	const struct option options[] = {

tools/perf/util/evlist.c

@@ -611,6 +611,8 @@ int perf_evlist__create_maps(struct perf_evlist *evlist,
 
 	if (perf_target__has_task(target))
 		evlist->cpus = cpu_map__dummy_new();
+	else if (!perf_target__has_cpu(target) && !target->uses_mmap)
+		evlist->cpus = cpu_map__dummy_new();
 	else
 		evlist->cpus = cpu_map__new(target->cpu_list);
 

tools/perf/util/target.h

@@ -11,6 +11,7 @@ struct perf_target {
 	const char   *uid_str;
 	uid_t	     uid;
 	bool	     system_wide;
+	bool	     uses_mmap;
 };
 
 enum perf_target_errno {