mm-Replace-cgroup_page-bit-spinlock.patch

From a2dad7e3d65db0e4eecdc89794d845e2ccef2f33 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 19 Aug 2009 09:56:42 +0200
Subject: [PATCH] mm: Replace cgroup_page bit spinlock

commit e3cf1fe8ff341a026b2128bb5c06dfbfd218df11 in tip.

Bit spinlocks are not working on RT. Replace them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 include/linux/page_cgroup.h |    5 +++--
 mm/page_cgroup.c            |    1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index aef22ae..f725d58 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -12,6 +12,7 @@
  */
 struct page_cgroup {
 	unsigned long flags;
+	spinlock_t lock;
 	struct mem_cgroup *mem_cgroup;
 	struct page *page;
 	struct list_head lru;		/* per cgroup LRU list */
@@ -91,12 +92,12 @@ static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
 
 static inline void lock_page_cgroup(struct page_cgroup *pc)
 {
-	bit_spin_lock(PCG_LOCK, &pc->flags);
+	spin_lock(&pc->lock);
 }
 
 static inline void unlock_page_cgroup(struct page_cgroup *pc)
 {
-	bit_spin_unlock(PCG_LOCK, &pc->flags);
+	spin_unlock(&pc->lock);
 }
 
 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 6c00814..d1a0982 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -14,6 +14,7 @@ static void __meminit
 __init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
 {
 	pc->flags = 0;
+	spin_lock_init(&pc->lock);
 	pc->mem_cgroup = NULL;
 	pc->page = pfn_to_page(pfn);
 	INIT_LIST_HEAD(&pc->lru);
-- 
1.7.0.4