Subject: mm/vmalloc: Another preempt disable region which sucks
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 12 Jul 2011 11:39:36 +0200
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: da77ceac3d20f27310a07a7c346a4ee6b40d6c28
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension

Avoid the preempt disable version of get_cpu_var(). The inner-lock should
provide enough serialisation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 mm/vmalloc.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1462,7 +1462,7 @@ static void *new_vmap_block(unsigned int
 	struct vmap_block *vb;
 	struct vmap_area *va;
 	unsigned long vb_idx;
-	int node, err;
+	int node, err, cpu;
 	void *vaddr;
 
 	node = numa_node_id();
@@ -1505,11 +1505,12 @@ static void *new_vmap_block(unsigned int
 	BUG_ON(err);
 	radix_tree_preload_end();
 
-	vbq = &get_cpu_var(vmap_block_queue);
+	cpu = get_cpu_light();
+	vbq = this_cpu_ptr(&vmap_block_queue);
 	spin_lock(&vbq->lock);
 	list_add_tail_rcu(&vb->free_list, &vbq->free);
 	spin_unlock(&vbq->lock);
-	put_cpu_var(vmap_block_queue);
+	put_cpu_light();
 
 	return vaddr;
 }
@@ -1578,6 +1579,7 @@ static void *vb_alloc(unsigned long size
 	struct vmap_block *vb;
 	void *vaddr = NULL;
 	unsigned int order;
+	int cpu;
 
 	BUG_ON(offset_in_page(size));
 	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
@@ -1592,7 +1594,8 @@ static void *vb_alloc(unsigned long size
 	order = get_order(size);
 
 	rcu_read_lock();
-	vbq = &get_cpu_var(vmap_block_queue);
+	cpu = get_cpu_light();
+	vbq = this_cpu_ptr(&vmap_block_queue);
 	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
 		unsigned long pages_off;
 
@@ -1615,7 +1618,7 @@ static void *vb_alloc(unsigned long size
 		break;
 	}
 
-	put_cpu_var(vmap_block_queue);
+	put_cpu_light();
 	rcu_read_unlock();
 
 	/* Allocate new block if nothing was found */