perf machine: Optimize a bit the machine__findnew_thread() methods

In some cases we already have calculated the hash bucket, so reuse it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Lukasz Odzioba <lukasz.odzioba@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-800zehjsyy03er4s4jf0e99v@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/machine.c

@@ -399,10 +399,10 @@ out_err:
  * lookup/new thread inserted.
  */
 static struct thread *____machine__findnew_thread(struct machine *machine,
+						  struct threads *threads,
 						  pid_t pid, pid_t tid,
 						  bool create)
 {
-	struct threads *threads = machine__threads(machine, tid);
 	struct rb_node **p = &threads->entries.rb_node;
 	struct rb_node *parent = NULL;
 	struct thread *th;
@@ -473,7 +473,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
 
 struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid)
 {
-	return ____machine__findnew_thread(machine, pid, tid, true);
+	return ____machine__findnew_thread(machine, machine__threads(machine, tid), pid, tid, true);
 }
 
 struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,
@@ -495,7 +495,7 @@ struct thread *machine__find_thread(struct machine *machine, pid_t pid,
 	struct thread *th;
 
 	pthread_rwlock_rdlock(&threads->lock);
-	th =  ____machine__findnew_thread(machine, pid, tid, false);
+	th =  ____machine__findnew_thread(machine, threads, pid, tid, false);
 	pthread_rwlock_unlock(&threads->lock);
 	return th;
 }