Slab allocators: Replace explicit zeroing with __GFP_ZERO

kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing
variant in the past.  But with __GFP_ZERO it is possible now to do zeroing
while allocating.

Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever
we can.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 18 insertions, 21 deletions

diff --git a/block/as-iosched.c b/block/as-iosched.c
index 109e91b91ffa..3e316dd72529 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -1322,10 +1322,9 @@ static void *as_init_queue(request_queue_t *q)
 {
         struct as_data *ad;
 
-        ad = kmalloc_node(sizeof(*ad), GFP_KERNEL, q->node);
+        ad = kmalloc_node(sizeof(*ad), GFP_KERNEL | __GFP_ZERO, q->node);
         if (!ad)
                 return NULL;
-        memset(ad, 0, sizeof(*ad));
 
         ad->q = q; /* Identify what queue the data belongs to */
 
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index e0aa4dad6742..9755a3cfad26 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1251,9 +1251,9 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
 {
         struct cfq_io_context *cic;
 
-        cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask, cfqd->queue->node);
+        cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO,
+                                                        cfqd->queue->node);
         if (cic) {
-                memset(cic, 0, sizeof(*cic));
                 cic->last_end_request = jiffies;
                 INIT_LIST_HEAD(&cic->queue_list);
                 cic->dtor = cfq_free_io_context;
@@ -1376,17 +1376,19 @@ retry:
                          * free memory.
                          */
                         spin_unlock_irq(cfqd->queue->queue_lock);
-                        new_cfqq = kmem_cache_alloc_node(cfq_pool, gfp_mask|__GFP_NOFAIL, cfqd->queue->node);
+                        new_cfqq = kmem_cache_alloc_node(cfq_pool,
+                                        gfp_mask | __GFP_NOFAIL | __GFP_ZERO,
+                                        cfqd->queue->node);
                         spin_lock_irq(cfqd->queue->queue_lock);
                         goto retry;
                 } else {
-                        cfqq = kmem_cache_alloc_node(cfq_pool, gfp_mask, cfqd->queue->node);
+                        cfqq = kmem_cache_alloc_node(cfq_pool,
+                                        gfp_mask | __GFP_ZERO,
+                                        cfqd->queue->node);
                         if (!cfqq)
                                 goto out;
                 }
 
-                memset(cfqq, 0, sizeof(*cfqq));
-
                 RB_CLEAR_NODE(&cfqq->rb_node);
                 INIT_LIST_HEAD(&cfqq->fifo);
 
@@ -2079,12 +2081,10 @@ static void *cfq_init_queue(request_queue_t *q)
 {
         struct cfq_data *cfqd;
 
-        cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node);
+        cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);
         if (!cfqd)
                 return NULL;
 
-        memset(cfqd, 0, sizeof(*cfqd));
-
         cfqd->service_tree = CFQ_RB_ROOT;
         INIT_LIST_HEAD(&cfqd->cic_list);
 
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index 6d673e938d3e..87ca02ac84cb 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -360,10 +360,9 @@ static void *deadline_init_queue(request_queue_t *q)
 {
         struct deadline_data *dd;
 
-        dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
+        dd = kmalloc_node(sizeof(*dd), GFP_KERNEL | __GFP_ZERO, q->node);
         if (!dd)
                 return NULL;
-        memset(dd, 0, sizeof(*dd));
 
         INIT_LIST_HEAD(&dd->fifo_list[READ]);
         INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
diff --git a/block/elevator.c b/block/elevator.c
index 4769a25d7037..d265963d1ed3 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -177,11 +177,10 @@ static elevator_t *elevator_alloc(request_queue_t *q, struct elevator_type *e)
         elevator_t *eq;
         int i;
 
-        eq = kmalloc_node(sizeof(elevator_t), GFP_KERNEL, q->node);
+        eq = kmalloc_node(sizeof(elevator_t), GFP_KERNEL | __GFP_ZERO, q->node);
         if (unlikely(!eq))
                 goto err;
 
-        memset(eq, 0, sizeof(*eq));
         eq->ops = &e->ops;
         eq->elevator_type = e;
         kobject_init(&eq->kobj);
diff --git a/block/genhd.c b/block/genhd.c
index 863a8c0623ed..b321cadd6e65 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -726,21 +726,21 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
 {
         struct gendisk *disk;
 
-        disk = kmalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
+        disk = kmalloc_node(sizeof(struct gendisk),
+                                GFP_KERNEL | __GFP_ZERO, node_id);
         if (disk) {
-                memset(disk, 0, sizeof(struct gendisk));
                 if (!init_disk_stats(disk)) {
                         kfree(disk);
                         return NULL;
                 }
                 if (minors > 1) {
                         int size = (minors - 1) * sizeof(struct hd_struct *);
-                        disk->part = kmalloc_node(size, GFP_KERNEL, node_id);
+                        disk->part = kmalloc_node(size,
+                                GFP_KERNEL | __GFP_ZERO, node_id);
                         if (!disk->part) {
                                 kfree(disk);
                                 return NULL;
                         }
-                        memset(disk->part, 0, size);
                 }
                 disk->minors = minors;
                 kobj_set_kset_s(disk,block_subsys);
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 11e4235d0b0c..d7cadf304168 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1829,11 +1829,11 @@ request_queue_t *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 {
         request_queue_t *q;
 
-        q = kmem_cache_alloc_node(requestq_cachep, gfp_mask, node_id);
+        q = kmem_cache_alloc_node(requestq_cachep,
+                                gfp_mask | __GFP_ZERO, node_id);
         if (!q)
                 return NULL;
 
-        memset(q, 0, sizeof(*q));
         init_timer(&q->unplug_timer);
 
         snprintf(q->kobj.name, KOBJ_NAME_LEN, "%s", "queue");