perf session: Move the global threads list to perf_session

So that we can process two perf.data files.

We still need to add a O_MMAP mode for perf_session so that we
can do all the mmap stuff in it.

Signed-off-by: Arnaldo Carvalho de Melo <acme@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: <1260741029-4430-5-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index b7eb3fc..d765323 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -63,7 +63,7 @@
 
 static u64			sample_type;
 
-static int process_sample_event(event_t *event, struct perf_session *session __used)
+static int process_sample_event(event_t *event, struct perf_session *session)
 {
 	struct sample_data data;
 	struct thread *thread;
@@ -81,7 +81,7 @@
 		(void *)(long)data.ip,
 		(long long)data.period);
 
-	thread = threads__findnew(event->ip.pid);
+	thread = perf_session__findnew(session, event->ip.pid);
 	if (thread == NULL) {
 		pr_debug("problem processing %d event, skipping it.\n",
 			 event->header.type);