[PATCH 1/2] mm, vmalloc: remove useless variable in vmap_block

[PATCH 1/2] mm, vmalloc: remove useless variable in vmap_block

[Joonsoo Kim]

vbq in vmap_block isn't used. So remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 13a5495..d23c432 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -752,7 +752,6 @@ struct vmap_block_queue {
 struct vmap_block {
 	spinlock_t lock;
 	struct vmap_area *va;
-	struct vmap_block_queue *vbq;
 	unsigned long free, dirty;
 	DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
 	struct list_head free_list;
@@ -830,7 +829,6 @@ static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
 	radix_tree_preload_end();
 
 	vbq = &get_cpu_var(vmap_block_queue);
-	vb->vbq = vbq;
 	spin_lock(&vbq->lock);
 	list_add_rcu(&vb->free_list, &vbq->free);
 	spin_unlock(&vbq->lock);
-- 
1.7.9.5

[PATCH 2/2] mm, vmalloc: use well-defined find_last_bit() func

[Joonsoo Kim]

Our intention in here is to find last_bit within the region to flush.
There is well-defined function, find_last_bit() for this purpose and
it's performance may be slightly better than current implementation.
So change it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d23c432..93d3182 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1016,15 +1016,16 @@ void vm_unmap_aliases(void)
 
 		rcu_read_lock();
 		list_for_each_entry_rcu(vb, &vbq->free, free_list) {
-			int i;
+			int i, j;
 
 			spin_lock(&vb->lock);
 			i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
-			while (i < VMAP_BBMAP_BITS) {
+			if (i < VMAP_BBMAP_BITS) {
 				unsigned long s, e;
-				int j;
-				j = find_next_zero_bit(vb->dirty_map,
-					VMAP_BBMAP_BITS, i);
+
+				j = find_last_bit(vb->dirty_map,
+							VMAP_BBMAP_BITS);
+				j = j + 1; /* need exclusive index */
 
 				s = vb->va->va_start + (i << PAGE_SHIFT);
 				e = vb->va->va_start + (j << PAGE_SHIFT);
@@ -1034,10 +1035,6 @@ void vm_unmap_aliases(void)
 					start = s;
 				if (e > end)
 					end = e;
-
-				i = j;
-				i = find_next_bit(vb->dirty_map,
-							VMAP_BBMAP_BITS, i);
 			}
 			spin_unlock(&vb->lock);
 		}
-- 
1.7.9.5

Re: [PATCH 2/2] mm, vmalloc: use well-defined find_last_bit() func

[Johannes Weiner]

On Fri, Aug 02, 2013 at 10:57:01AM +0900, Joonsoo Kim wrote:
> Our intention in here is to find last_bit within the region to flush.
> There is well-defined function, find_last_bit() for this purpose and
> it's performance may be slightly better than current implementation.
> So change it.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Re: [PATCH 1/2] mm, vmalloc: remove useless variable in vmap_block

[Johannes Weiner]

On Fri, Aug 02, 2013 at 10:57:00AM +0900, Joonsoo Kim wrote:
> vbq in vmap_block isn't used. So remove it.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>