5 files changed, 37 insertions, 45 deletions

diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index 5d0f93c..0daacb9 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -96,3 +96,19 @@ unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set)
 	kfree(map);
 	return NULL;
 }
+
+/*
+ * We have no quick way of doing reverse lookups. This is only used at
+ * queue init time, so runtime isn't important.
+ */
+int blk_mq_hw_queue_to_node(unsigned int *mq_map, unsigned int index)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		if (index == mq_map[i])
+			return cpu_to_node(i);
+	}
+
+	return NUMA_NO_NODE;
+}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e8b5f74..30bad93 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1297,10 +1297,10 @@ struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu)
 EXPORT_SYMBOL(blk_mq_map_queue);
 
 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *set,
-						   unsigned int hctx_index)
+						   unsigned int hctx_index,
+						   int node)
 {
-	return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL,
-				set->numa_node);
+	return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, node);
 }
 EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue);
 
@@ -1752,6 +1752,7 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 	struct blk_mq_hw_ctx **hctxs;
 	struct blk_mq_ctx *ctx;
 	struct request_queue *q;
+	unsigned int *map;
 	int i;
 
 	ctx = alloc_percpu(struct blk_mq_ctx);
@@ -1764,8 +1765,14 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 	if (!hctxs)
 		goto err_percpu;
 
+	map = blk_mq_make_queue_map(set);
+	if (!map)
+		goto err_map;
+
 	for (i = 0; i < set->nr_hw_queues; i++) {
-		hctxs[i] = set->ops->alloc_hctx(set, i);
+		int node = blk_mq_hw_queue_to_node(map, i);
+
+		hctxs[i] = set->ops->alloc_hctx(set, i, node);
 		if (!hctxs[i])
 			goto err_hctxs;
 
@@ -1773,7 +1780,7 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 			goto err_hctxs;
 
 		atomic_set(&hctxs[i]->nr_active, 0);
-		hctxs[i]->numa_node = NUMA_NO_NODE;
+		hctxs[i]->numa_node = node;
 		hctxs[i]->queue_num = i;
 	}
 
@@ -1784,15 +1791,12 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 	if (percpu_counter_init(&q->mq_usage_counter, 0))
 		goto err_map;
 
-	q->mq_map = blk_mq_make_queue_map(set);
-	if (!q->mq_map)
-		goto err_map;
-
 	setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q);
 	blk_queue_rq_timeout(q, 30000);
 
 	q->nr_queues = nr_cpu_ids;
 	q->nr_hw_queues = set->nr_hw_queues;
+	q->mq_map = map;
 
 	q->queue_ctx = ctx;
 	q->queue_hw_ctx = hctxs;
@@ -1844,16 +1848,16 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 err_flush_rq:
 	kfree(q->flush_rq);
 err_hw:
-	kfree(q->mq_map);
-err_map:
 	blk_cleanup_queue(q);
 err_hctxs:
+	kfree(map);
 	for (i = 0; i < set->nr_hw_queues; i++) {
 		if (!hctxs[i])
 			break;
 		free_cpumask_var(hctxs[i]->cpumask);
 		set->ops->free_hctx(hctxs[i], i);
 	}
+err_map:
 	kfree(hctxs);
 err_percpu:
 	free_percpu(ctx);
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 491dbd4..ff5e6bf 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -52,6 +52,7 @@ void blk_mq_disable_hotplug(void);
  */
 extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
 extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
+extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
 
 /*
  * Basic implementation of sparser bitmap, allowing the user to spread
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 8e7e3a0..4d33c8c 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -322,39 +322,10 @@ static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq)
 }
 
 static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_tag_set *set,
-		unsigned int hctx_index)
+					     unsigned int hctx_index,
+					     int node)
 {
-	int b_size = DIV_ROUND_UP(set->nr_hw_queues, nr_online_nodes);
-	int tip = (set->nr_hw_queues % nr_online_nodes);
-	int node = 0, i, n;
-
-	/*
-	 * Split submit queues evenly wrt to the number of nodes. If uneven,
-	 * fill the first buckets with one extra, until the rest is filled with
-	 * no extra.
-	 */
-	for (i = 0, n = 1; i < hctx_index; i++, n++) {
-		if (n % b_size == 0) {
-			n = 0;
-			node++;
-
-			tip--;
-			if (!tip)
-				b_size = set->nr_hw_queues / nr_online_nodes;
-		}
-	}
-
-	/*
-	 * A node might not be online, therefore map the relative node id to the
-	 * real node id.
-	 */
-	for_each_online_node(n) {
-		if (!node)
-			break;
-		node--;
-	}
-
-	return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, n);
+	return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, node);
 }
 
 static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index)
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index f76bb18..afeb934 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -80,7 +80,7 @@ struct blk_mq_tag_set {
 typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
 typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_tag_set *,
-		unsigned int);
+		unsigned int, int);
 typedef void (free_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
@@ -165,7 +165,7 @@ struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, g
 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 
 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
-struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int);
+struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
 void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
 
 void blk_mq_end_io(struct request *rq, int error);