Re: Kernel crashes after 529262d56dbe "block: remove ->poll_fn"

[Christoph Hellwig <hch@lst.de>]

On Wed, Dec 05, 2018 at 06:39:26AM -0700, Jens Axboe wrote:
> > What device is this?
> 
> This might also help...

Yes, it should.  I had missed that we turned on QUEUE_FLAG_POLL
by default, which is rather odd.  The even weirder things is that
git-blame claims it was me who enabled it :)

> 
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 0b3874bdbc6a..81f1b105946b 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -606,8 +606,7 @@ struct request_queue {
>  				 (1 << QUEUE_FLAG_ADD_RANDOM))
>  
>  #define QUEUE_FLAG_MQ_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
> -				 (1 << QUEUE_FLAG_SAME_COMP)	|	\
> -				 (1 << QUEUE_FLAG_POLL))
> +				 (1 << QUEUE_FLAG_SAME_COMP))
>  
>  void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
>  void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
> 
> -- 
> Jens Axboe
---end quoted text---