This comment is very useful, thanks for this patch.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
On 2/20/20 7:23 PM, Bart Van Assche wrote:
> blk_mq_map_queues() and multiple .map_queues() implementations expect that
> set->map[HCTX_TYPE_DEFAULT].nr_queues is set to the number of hardware
> queues. Hence set .nr_queues before calling these functions. This patch
> fixes the following kernel warning:
>
> WARNING: CPU: 0 PID: 2501 at include/linux/cpumask.h:137
> Call Trace:
> blk_mq_run_hw_queue+0x19d/0x350 block/blk-mq.c:1508
> blk_mq_run_hw_queues+0x112/0x1a0 block/blk-mq.c:1525
> blk_mq_requeue_work+0x502/0x780 block/blk-mq.c:775
> process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
> worker_thread+0x98/0xe40 kernel/workqueue.c:2415
> kthread+0x361/0x430 kernel/kthread.c:255
>
> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
> Cc: Ming Lei <ming.lei@xxxxxxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxxx>
> Cc: Johannes Thumshirn <jth@xxxxxxxxxx>
> Reported-by: syzbot+d44e1b26ce5c3e77458d@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: ed76e329d74a ("blk-mq: abstract out queue map") # v5.0
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
