linux-kernel - [RFC][PATCH 6/7] rbtree, rtmutex: Use rb_add

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 29 Apr 2020 17:33:04 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     linux-kernel@...r.kernel.org
Cc:     walken@...gle.com, dave@...olabs.net, mingo@...nel.org,
        tglx@...utronix.de, oleg@...hat.com, irogers@...gle.com,
        juri.lelli@...hat.com, vincent.guittot@...aro.org,
        peterz@...radead.org
Subject: [RFC][PATCH 6/7] rbtree, rtmutex: Use rb_add_cached()


Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 kernel/locking/rtmutex.c |   54 +++++++++++++++--------------------------------
 1 file changed, 18 insertions(+), 36 deletions(-)

--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -267,27 +267,18 @@ rt_mutex_waiter_equal(struct rt_mutex_wa
 	return 1;
 }
 
+#define __node_2_waiter(node) \
+	rb_entry((node), struct rt_mutex_waiter, tree_entry)
+
+static inline bool __waiter_less(struct rb_node *a, const struct rb_node *b)
+{
+	return rt_mutex_waiter_less(__node_2_waiter(a), __node_2_waiter(b));
+}
+
 static void
 rt_mutex_enqueue(struct rt_mutex *lock, struct rt_mutex_waiter *waiter)
 {
-	struct rb_node **link = &lock->waiters.rb_root.rb_node;
-	struct rb_node *parent = NULL;
-	struct rt_mutex_waiter *entry;
-	bool leftmost = true;
-
-	while (*link) {
-		parent = *link;
-		entry = rb_entry(parent, struct rt_mutex_waiter, tree_entry);
-		if (rt_mutex_waiter_less(waiter, entry)) {
-			link = &parent->rb_left;
-		} else {
-			link = &parent->rb_right;
-			leftmost = false;
-		}
-	}
-
-	rb_link_node(&waiter->tree_entry, parent, link);
-	rb_insert_color_cached(&waiter->tree_entry, &lock->waiters, leftmost);
+	rb_add_cached(&lock->waiters, &waiter->tree_entry, __waiter_less);
 }
 
 static void
@@ -300,27 +291,18 @@ rt_mutex_dequeue(struct rt_mutex *lock,
 	RB_CLEAR_NODE(&waiter->tree_entry);
 }
 
+#define __node_2_pi_waiter(node) \
+	rb_entry((node), struct rt_mutex_waiter, pi_tree_entry)
+
+static inline bool __pi_waiter_less(struct rb_node *a, const struct rb_node *b)
+{
+	return rt_mutex_waiter_less(__node_2_pi_waiter(a), __node_2_pi_waiter(b));
+}
+
 static void
 rt_mutex_enqueue_pi(struct task_struct *task, struct rt_mutex_waiter *waiter)
 {
-	struct rb_node **link = &task->pi_waiters.rb_root.rb_node;
-	struct rb_node *parent = NULL;
-	struct rt_mutex_waiter *entry;
-	bool leftmost = true;
-
-	while (*link) {
-		parent = *link;
-		entry = rb_entry(parent, struct rt_mutex_waiter, pi_tree_entry);
-		if (rt_mutex_waiter_less(waiter, entry)) {
-			link = &parent->rb_left;
-		} else {
-			link = &parent->rb_right;
-			leftmost = false;
-		}
-	}
-
-	rb_link_node(&waiter->pi_tree_entry, parent, link);
-	rb_insert_color_cached(&waiter->pi_tree_entry, &task->pi_waiters, leftmost);
+	rb_add_cached(&task->pi_waiters, &waiter->pi_tree_entry, __pi_waiter_less);
 }
 
 static void