block: allocate request memory local to request queue

blk_init_rl() allocates a mempool using mempool_create_node() with node local memory. This only allocates the mempool and element list locally to the requeue queue node. What we really want to do is allocate the request itself local to the queue. To do this, we need our own alloc and free functions that will allocate from request_cachep and pass the request queue node in to prefer node local memory. Acked-by: Tejun Heo <[email protected]> Signed-off-by: David Rientjes <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
chewitt · Mar 25, 2015 · 271508d · 271508d
1 parent bfd343a
commit 271508d
Showing 1 changed file with 16 additions and 3 deletions.
diff --git a/block/blk-core.c b/block/blk-core.c
@@ -557,6 +557,18 @@ void blk_cleanup_queue(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_cleanup_queue);
 
+/* Allocate memory local to the request queue */
+static void *alloc_request_struct(gfp_t gfp_mask, void *data)
+{
+	int nid = (int)(long)data;
+	return kmem_cache_alloc_node(request_cachep, gfp_mask, nid);
+}
+
+static void free_request_struct(void *element, void *unused)
+{
+	kmem_cache_free(request_cachep, element);
+}
+
 int blk_init_rl(struct request_list *rl, struct request_queue *q,
 		gfp_t gfp_mask)
 {
@@ -569,9 +581,10 @@ int blk_init_rl(struct request_list *rl, struct request_queue *q,
 	init_waitqueue_head(&rl->wait[BLK_RW_SYNC]);
 	init_waitqueue_head(&rl->wait[BLK_RW_ASYNC]);
 
-	rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
-					  mempool_free_slab, request_cachep,
-					  gfp_mask, q->node);
+	rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, alloc_request_struct,
+					  free_request_struct,
+					  (void *)(long)q->node, gfp_mask,
+					  q->node);
 	if (!rl->rq_pool)
 		return -ENOMEM;