perf session: Create kernel maps in the constructor

Removing one extra step needed in the tools that need this,
fixing a bug in 'perf probe' where this was not being done.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1264633557-17597-4-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/builtin-kmem.c

@@ -491,11 +491,6 @@ static int __cmd_kmem(void)
 	if (!perf_session__has_traces(session, "kmem record"))
 		goto out_delete;
 
-	if (perf_session__create_kernel_maps(session) < 0) {
-		pr_err("Problems creating kernel maps\n");
-		return -1;
-	}
-
 	setup_pager();
 	err = perf_session__process_events(session, &event_ops);
 	if (err != 0)

tools/perf/builtin-record.c

@@ -477,11 +477,6 @@ static int __cmd_record(int argc, const char **argv)
 		return -1;
 	}
 
-	if (perf_session__create_kernel_maps(session) < 0) {
-		pr_err("Problems creating kernel maps\n");
-		return -1;
-	}
-
 	if (!file_new) {
 		err = perf_header__read(&session->header, output);
 		if (err < 0)

tools/perf/builtin-top.c

@@ -1191,11 +1191,6 @@ static int __cmd_top(void)
 	if (session == NULL)
 		return -ENOMEM;
 
-	if (perf_session__create_kernel_maps(session) < 0) {
-		pr_err("Problems creating kernel maps\n");
-		return -1;
-	}
-
 	if (target_pid != -1)
 		event__synthesize_thread(target_pid, event__process, session);
 	else

tools/perf/util/session.c

@@ -70,8 +70,17 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc
 	self->unknown_events = 0;
 	map_groups__init(&self->kmaps);
 
-	if (mode == O_RDONLY && perf_session__open(self, force) < 0)
-		goto out_delete;
+	if (mode == O_RDONLY) {
+		if (perf_session__open(self, force) < 0)
+			goto out_delete;
+	} else if (mode == O_WRONLY) {
+		/*
+		 * In O_RDONLY mode this will be performed when reading the
+		 * kernel MMAP event, in event__process_mmap().
+		 */
+		if (perf_session__create_kernel_maps(self) < 0)
+			goto out_delete;
+	}
 
 	self->sample_type = perf_header__sample_type(&self->header);
 out: