[PATCH v1 0/3] blk-mq: misc changes

[PATCH v1 0/3] blk-mq: misc changes

[Ming Lei]

Hi,

Misc changes, and the v1 is against the latest for-next
branch of block tree.

Thanks,
--
Ming Lei

[PATCH v1 1/3] blk-mq: fix leak of hctx->ctx_map

[Ming Lei]

hctx->ctx_map should have been freed inside blk_mq_free_queue().

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 block/blk-mq.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 62082c5..dad22a9 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1846,6 +1846,7 @@ void blk_mq_free_queue(struct request_queue *q)
 	queue_for_each_hw_ctx(q, hctx, i) {
 		blk_mq_tag_idle(hctx);
 		kfree(hctx->ctxs);
+		blk_mq_free_bitmap(&hctx->ctx_map);
 		blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
 		if (q->mq_ops->exit_hctx)
 			q->mq_ops->exit_hctx(hctx, i);
-- 
1.7.9.5

[PATCH v1 2/3] blk-mq: avoid code duplication

[Ming Lei]

blk_mq_exit_hw_queues() and blk_mq_free_hw_queues()
are introduced to avoid code duplication.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 block/blk-mq.c |   61 ++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 37 insertions(+), 24 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index dad22a9..0785175 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1523,11 +1523,43 @@ static int blk_mq_hctx_notify(void *data, unsigned long action,
 	return NOTIFY_OK;
 }
 
+static void blk_mq_exit_hw_queues(struct request_queue *q,
+		struct blk_mq_tag_set *set, int nr_queue)
+{
+	struct blk_mq_hw_ctx *hctx;
+	unsigned int i;
+
+	queue_for_each_hw_ctx(q, hctx, i) {
+		if (i == nr_queue)
+			break;
+
+		if (set->ops->exit_hctx)
+			set->ops->exit_hctx(hctx, i);
+
+		blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
+		kfree(hctx->ctxs);
+		blk_mq_free_bitmap(&hctx->ctx_map);
+	}
+
+}
+
+static void blk_mq_free_hw_queues(struct request_queue *q,
+		struct blk_mq_tag_set *set)
+{
+	struct blk_mq_hw_ctx *hctx;
+	unsigned int i;
+
+	queue_for_each_hw_ctx(q, hctx, i) {
+		free_cpumask_var(hctx->cpumask);
+		set->ops->free_hctx(hctx, i);
+	}
+}
+
 static int blk_mq_init_hw_queues(struct request_queue *q,
 		struct blk_mq_tag_set *set)
 {
 	struct blk_mq_hw_ctx *hctx;
-	unsigned int i, j;
+	unsigned int i;
 
 	/*
 	 * Initialize hardware queues
@@ -1579,17 +1611,7 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
 	/*
 	 * Init failed
 	 */
-	queue_for_each_hw_ctx(q, hctx, j) {
-		if (i == j)
-			break;
-
-		if (set->ops->exit_hctx)
-			set->ops->exit_hctx(hctx, j);
-
-		blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
-		kfree(hctx->ctxs);
-		blk_mq_free_bitmap(&hctx->ctx_map);
-	}
+	blk_mq_exit_hw_queues(q, set, i);
 
 	return 1;
 }
@@ -1838,21 +1860,12 @@ EXPORT_SYMBOL(blk_mq_init_queue);
 
 void blk_mq_free_queue(struct request_queue *q)
 {
-	struct blk_mq_hw_ctx *hctx;
-	int i;
+	struct blk_mq_tag_set	*set = q->tag_set;
 
 	blk_mq_del_queue_tag_set(q);
 
-	queue_for_each_hw_ctx(q, hctx, i) {
-		blk_mq_tag_idle(hctx);
-		kfree(hctx->ctxs);
-		blk_mq_free_bitmap(&hctx->ctx_map);
-		blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
-		if (q->mq_ops->exit_hctx)
-			q->mq_ops->exit_hctx(hctx, i);
-		free_cpumask_var(hctx->cpumask);
-		q->mq_ops->free_hctx(hctx, i);
-	}
+	blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
+	blk_mq_free_hw_queues(q, set);
 
 	free_percpu(q->queue_ctx);
 	kfree(q->queue_hw_ctx);
-- 
1.7.9.5

[PATCH v1 3/3] block: only allocate/free mq_usage_counter in blk-mq

[Ming Lei]

The percpu counter is only used for blk-mq, so move
its allocation and free inside blk-mq, and don't
allocate it for legacy queue device.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 block/blk-core.c  |    7 +------
 block/blk-mq.c    |    5 +++++
 block/blk-sysfs.c |    2 --
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 5b6f768..29d5fba 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -576,12 +576,9 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 	if (!q)
 		return NULL;
 
-	if (percpu_counter_init(&q->mq_usage_counter, 0))
-		goto fail_q;
-
 	q->id = ida_simple_get(&blk_queue_ida, 0, 0, gfp_mask);
 	if (q->id < 0)
-		goto fail_c;
+		goto fail_q;
 
 	q->backing_dev_info.ra_pages =
 			(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
@@ -639,8 +636,6 @@ fail_bdi:
 	bdi_destroy(&q->backing_dev_info);
 fail_id:
 	ida_simple_remove(&blk_queue_ida, q->id);
-fail_c:
-	percpu_counter_destroy(&q->mq_usage_counter);
 fail_q:
 	kmem_cache_free(blk_requestq_cachep, q);
 	return NULL;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0785175..e8b5f74 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1781,6 +1781,9 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 	if (!q)
 		goto err_hctxs;
 
+	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;
@@ -1867,6 +1870,8 @@ void blk_mq_free_queue(struct request_queue *q)
 	blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
 	blk_mq_free_hw_queues(q, set);
 
+	percpu_counter_destroy(&q->mq_usage_counter);
+
 	free_percpu(q->queue_ctx);
 	kfree(q->queue_hw_ctx);
 	kfree(q->mq_map);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 4d6811a..23321fb 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -517,8 +517,6 @@ static void blk_release_queue(struct kobject *kobj)
 	if (q->queue_tags)
 		__blk_queue_free_tags(q);
 
-	percpu_counter_destroy(&q->mq_usage_counter);
-
 	if (q->mq_ops)
 		blk_mq_free_queue(q);
 
-- 
1.7.9.5

Re: [PATCH v1 0/3] blk-mq: misc changes

[Jens Axboe]

On 2014-05-27 09:35, Ming Lei wrote:
> Hi,
>
> Misc changes, and the v1 is against the latest for-next
> branch of block tree.

Applied 2+3 (1 I already hand applied). Thanks Ming! I really appreciate 
you finding and fixing these issues.

-- 
Jens Axboe