[PATCH 14/21] blk-mq: Rework blk_mq_init_hctx() function

From: Alexander Gordeev
Date: Fri Sep 16 2016 - 04:54:26 EST


Rework blk_mq_init_hctx() function so all reaquired memory
allocations are done before data initialization and callbacks
invocation.

CC: Jens Axboe <axboe@xxxxxxxxx>
CC: linux-nvme@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
---
block/blk-mq.c | 50 ++++++++++++++++++++++++--------------------------
1 file changed, 24 insertions(+), 26 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index b77e73b..9e5cd1f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1712,6 +1712,22 @@ static struct blk_mq_hw_ctx *blk_mq_init_hctx(struct request_queue *q,
if (!zalloc_cpumask_var_node(&hctx->cpumask, GFP_KERNEL, node))
goto free_hctx;

+ /*
+ * Allocate space for all possible cpus to avoid allocation at
+ * runtime
+ */
+ hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
+ GFP_KERNEL, node);
+ if (!hctx->ctxs)
+ goto free_cpumask;
+
+ if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
+ goto free_ctxs;
+
+ hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
+ if (!hctx->fq)
+ goto free_bitmap;
+
INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
spin_lock_init(&hctx->lock);
@@ -1720,55 +1736,37 @@ static struct blk_mq_hw_ctx *blk_mq_init_hctx(struct request_queue *q,
hctx->numa_node = node;
hctx->queue = q;
hctx->queue_num = hctx_idx;
+ hctx->nr_ctx = 0;
hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED;
+ hctx->tags = set->tags[hctx_idx];

blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
blk_mq_hctx_notify, hctx);
blk_mq_register_cpu_notifier(&hctx->cpu_notifier);

- hctx->tags = set->tags[hctx_idx];
-
- /*
- * Allocate space for all possible cpus to avoid allocation at
- * runtime
- */
- hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
- GFP_KERNEL, node);
- if (!hctx->ctxs)
- goto unregister_cpu_notifier;
-
- if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
- goto free_ctxs;
-
- hctx->nr_ctx = 0;
-
if (set->ops->init_hctx &&
set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
- goto free_bitmap;
-
- hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
- if (!hctx->fq)
- goto exit_hctx;
+ goto unregister_cpu_notifier;

if (set->ops->init_request &&
set->ops->init_request(set->driver_data,
hctx->fq->flush_rq, hctx_idx,
flush_start_tag + hctx_idx, node))
- goto free_fq;
+ goto exit_hctx;

return hctx;

- free_fq:
- kfree(hctx->fq);
exit_hctx:
if (set->ops->exit_hctx)
set->ops->exit_hctx(hctx, hctx_idx);
+ unregister_cpu_notifier:
+ blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
+ kfree(hctx->fq);
free_bitmap:
blk_mq_free_bitmap(&hctx->ctx_map);
free_ctxs:
kfree(hctx->ctxs);
- unregister_cpu_notifier:
- blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
+ free_cpumask:
free_cpumask_var(hctx->cpumask);
free_hctx:
kfree(hctx);
--
1.8.3.1