Re: [PATCH 4/5] blk-mq-debugfs: Show busy requests

Jens Axboe
2017-05-26T13:26:56Z

On 05/25/2017 05:38 PM, Bart Van Assche wrote:
> Requests that got stuck in a block driver are neither on
> blk_mq_ctx.rq_list nor on any hw dispatch queue. Make these
> visible in debugfs through the "busy" attribute.
>
> Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Hannes Reinecke <hare@suse.com>
> Cc: Omar Sandoval <osandov@fb.com>
> Cc: Ming Lei <ming.lei@redhat.com>
> ---
> block/blk-mq-debugfs.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
> index 8b06a12c1461..70a2b955afee 100644
> --- a/block/blk-mq-debugfs.c
> +++ b/block/blk-mq-debugfs.c
> @@ -370,6 +370,30 @@ static const struct seq_operations hctx_dispatch_seq_ops = {
> .show = blk_mq_debugfs_rq_show,
> };
>
> +struct show_busy_ctx {
> + struct seq_file *m;
> + struct blk_mq_hw_ctx *hctx;
> +};
> +
> +static void hctx_show_busy(struct request *rq, void *data, bool reserved)
> +{
> + const struct show_busy_ctx *ctx = data;

Let's not call that variable 'ctx', in blk-mq that's pretty much
reserved for the sw queues.

--
Jens Axboe