4 files changed, 33 insertions, 21 deletions

diff --git a/block/blk-mq-cpu.c b/block/blk-mq-cpu.c
index d2c253f71b86..bb3ed488f7b5 100644
--- a/block/blk-mq-cpu.c
+++ b/block/blk-mq-cpu.c
@@ -1,3 +1,8 @@
+/*
+ * CPU notifier helper code for blk-mq
+ *
+ * Copyright (C) 2013-2014 Jens Axboe
+ */
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index 0daacb927be1..1065d7c65fa1 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -1,3 +1,8 @@
+/*
+ * CPU <-> hardware queue mapping helpers
+ *
+ * Copyright (C) 2013-2014 Jens Axboe
+ */
 #include <linux/kernel.h>
 #include <linux/threads.h>
 #include <linux/module.h>
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 0d0640d38a06..d90c4aeb7dd3 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -1,3 +1,15 @@
+/*
+ * Fast and scalable bitmap tagging variant. Uses sparser bitmaps spread
+ * over multiple cachelines to avoid ping-pong between multiple submitters
+ * or submitter and completer. Uses rolling wakeups to avoid falling of
+ * the scaling cliff when we run out of tags and have to start putting
+ * submitters to sleep.
+ *
+ * Uses active queue tracking to support fairer distribution of tags
+ * between multiple submitters when a shared tag map is used.
+ *
+ * Copyright (C) 2013-2014 Jens Axboe
+ */
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/random.h>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ae14749b530c..f27fe44230c2 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1,3 +1,9 @@
+/*
+ * Block multiqueue core code
+ *
+ * Copyright (C) 2013-2014 Jens Axboe
+ * Copyright (C) 2013-2014 Christoph Hellwig
+ */
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/backing-dev.h>
@@ -1329,21 +1335,6 @@ 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,
-                                                   int node)
-{
-        return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, node);
-}
-EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue);
-
-void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *hctx,
-                                 unsigned int hctx_index)
-{
-        kfree(hctx);
-}
-EXPORT_SYMBOL(blk_mq_free_single_hw_queue);
-
 static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
                 struct blk_mq_tags *tags, unsigned int hctx_idx)
 {
@@ -1584,7 +1575,7 @@ static void blk_mq_free_hw_queues(struct request_queue *q,
 
         queue_for_each_hw_ctx(q, hctx, i) {
                 free_cpumask_var(hctx->cpumask);
-                set->ops->free_hctx(hctx, i);
+                kfree(hctx);
         }
 }
 
@@ -1805,7 +1796,8 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
         for (i = 0; i < set->nr_hw_queues; i++) {
                 int node = blk_mq_hw_queue_to_node(map, i);
 
-                hctxs[i] = set->ops->alloc_hctx(set, i, node);
+                hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx),
+                                        GFP_KERNEL, node);
                 if (!hctxs[i])
                         goto err_hctxs;
 
@@ -1892,7 +1884,7 @@ err_hctxs:
                 if (!hctxs[i])
                         break;
                 free_cpumask_var(hctxs[i]->cpumask);
-                set->ops->free_hctx(hctxs[i], i);
+                kfree(hctxs[i]);
         }
 err_map:
         kfree(hctxs);
@@ -1977,9 +1969,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
         if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
                 return -EINVAL;
 
-        if (!set->nr_hw_queues ||
-            !set->ops->queue_rq || !set->ops->map_queue ||
-            !set->ops->alloc_hctx || !set->ops->free_hctx)
+        if (!set->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue)
                 return -EINVAL;