From ca986f998bcfd093e6c0bcbd2f145231fde48617 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Wed, 3 Jun 2009 19:59:24 +0200
Subject: [PATCH] --- yaml --- r: 147634 b: refs/heads/master c:
 eed4dcd443da7a46131ef37c7a389b444905960e h: refs/heads/master v: v3

---
 [refs]                                            |  2 +-
 trunk/Documentation/perf_counter/builtin-report.c | 15 ++++++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 702da655bf8c..717eef8a9045 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 44db76c8553c328f4ae02481d77bb3a88ca17645
+refs/heads/master: eed4dcd443da7a46131ef37c7a389b444905960e
diff --git a/trunk/Documentation/perf_counter/builtin-report.c b/trunk/Documentation/perf_counter/builtin-report.c
index e837bb983dca..33b3b15fb014 100644
--- a/trunk/Documentation/perf_counter/builtin-report.c
+++ b/trunk/Documentation/perf_counter/builtin-report.c
@@ -229,6 +229,7 @@ static int thread__set_comm(struct thread *self, const char *comm)
 }
 
 static struct rb_root threads;
+static struct thread *last_match;
 
 static struct thread *threads__findnew(pid_t pid)
 {
@@ -236,12 +237,22 @@ static struct thread *threads__findnew(pid_t pid)
 	struct rb_node *parent = NULL;
 	struct thread *th;
 
+	/*
+	 * Font-end cache - PID lookups come in blocks,
+	 * so most of the time we dont have to look up
+	 * the full rbtree:
+	 */
+	if (last_match && last_match->pid == pid)
+		return last_match;
+
 	while (*p != NULL) {
 		parent = *p;
 		th = rb_entry(parent, struct thread, rb_node);
 
-		if (th->pid == pid)
+		if (th->pid == pid) {
+			last_match = th;
 			return th;
+		}
 
 		if (pid < th->pid)
 			p = &(*p)->rb_left;
@@ -253,7 +264,9 @@ static struct thread *threads__findnew(pid_t pid)
 	if (th != NULL) {
 		rb_link_node(&th->rb_node, parent, p);
 		rb_insert_color(&th->rb_node, &threads);
+		last_match = th;
 	}
+
 	return th;
 }