linux/debian/patches-rt/0178-mm-vmalloc-Another-preempt-disable-region-which-suck.patch

From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 12 Jul 2011 11:39:36 +0200
Subject: [PATCH 178/290] mm/vmalloc: Another preempt disable region which
 sucks
Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=984f0aea9084e80c662e605b8683389dd685232d

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

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

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d8e877365f9f..9b7cf993cada 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -852,7 +852,7 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 	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();
@@ -895,11 +895,12 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 	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;
 }
@@ -968,6 +969,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 	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);
@@ -982,7 +984,8 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 	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;
 
@@ -1005,7 +1008,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
 		break;
 	}
 
-	put_cpu_var(vmap_block_queue);
+	put_cpu_light();
 	rcu_read_unlock();
 
 	/* Allocate new block if nothing was found */