On Wed, May 03, 2023 at 04:06:53PM -0700, Bart Van Assche wrote:
> Instead of running the request queue of each device associated with a
> host every 3 ms (BLK_MQ_RESOURCE_DELAY) while host error handling is in
> progress, run the request queue after error handling has finished.
>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Ming Lei <ming.lei@xxxxxxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxx>
> Cc: John Garry <john.g.garry@xxxxxxxxxx>
> Cc: Mike Christie <michael.christie@xxxxxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> drivers/scsi/scsi_lib.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index e59eb0cbfc83..a34390d35f1d 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -122,11 +122,9 @@ static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd, unsigned long msecs)
> WARN_ON_ONCE(true);
> }
>
> - if (msecs) {
> - blk_mq_requeue_request(rq, false);
> + blk_mq_requeue_request(rq, false);
> + if (!scsi_host_in_recovery(cmd->device->host))
> blk_mq_delay_kick_requeue_list(rq->q, msecs);
> - } else
> - blk_mq_requeue_request(rq, true);
> }
>
> /**
> @@ -165,7 +163,8 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
> */
> cmd->result = 0;
>
> - blk_mq_requeue_request(scsi_cmd_to_rq(cmd), true);
> + blk_mq_requeue_request(scsi_cmd_to_rq(cmd),
> + !scsi_host_in_recovery(cmd->device->host));
> }
>
> /**
> @@ -462,10 +461,16 @@ void scsi_requeue_run_queue(struct work_struct *work)
> scsi_run_queue(q);
> }
>
> +/*
> + * Transfer requests from the requeue_list to from where these can be dispatched
> + * and run the request queues.
> + */
> void scsi_run_host_queues(struct Scsi_Host *shost)
> {
> struct scsi_device *sdev;
>
> + shost_for_each_device(sdev, shost)
> + blk_mq_kick_requeue_list(sdev->request_queue);
> shost_for_each_device(sdev, shost)
> scsi_run_queue(sdev->request_queue);
You may move blk_mq_kick_requeue_list() to the following loop, or even
inside scsi_run_queue(), which isn't called in fast patch.
Thanks,
Ming
