perf machine: No need to keep a refcnt for last_match

Since it is all associated with the refcount for keeping the thread
in the rbtree, it is excessive and unecessarily complex to hold a
refcont when changing machine->last_match.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-98kuesmfwtvhsrzx7ttyb0kt@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 8b0b307d91f48447996a50dfb6ecc3b9234b9e1b..34bf89f7f4f36f72f13b645dde1b022ebe7ae7d8 100644 (file)
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -364,7 +364,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
                        return th;
                }
 
-               thread__zput(machine->last_match);
+               machine->last_match = NULL;
        }
 
        while (*p != NULL) {
@@ -372,7 +372,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
                th = rb_entry(parent, struct thread, rb_node);
 
                if (th->tid == tid) {
-                       machine->last_match = thread__get(th);
+                       machine->last_match = th;
                        machine__update_thread_pid(machine, th, pid);
                        return th;
                }
@@ -409,7 +409,7 @@ static struct thread *____machine__findnew_thread(struct machine *machine,
                 * It is now in the rbtree, get a ref
                 */
                thread__get(th);
-               machine->last_match = thread__get(th);
+               machine->last_match = th;
        }
 
        return th;
@@ -1309,7 +1309,7 @@ out_problem:
 static void __machine__remove_thread(struct machine *machine, struct thread *th, bool lock)
 {
        if (machine->last_match == th)
-               thread__zput(machine->last_match);
+               machine->last_match = NULL;
 
        BUG_ON(th->refcnt.counter == 0);
        if (lock)