Re: [PATCH] SCSI: run queue if SCSI device queue isn't ready and queue is idle

[Bart Van Assche]

On Thu, 2017-12-07 at 09:31 +0800, Ming Lei wrote:
> But if you always call blk_mq_sched_mark_restart_hctx() before a new
> dispatch, that may affect performance on NVMe which may never trigger
> BLK_STS_RESOURCE.

Hmm ... only the SCSI core implements .get_budget() and .put_budget() and
I proposed to insert a blk_mq_sched_mark_restart_hctx() call under "if
(q->mq_ops->get_budget)". In other words, I proposed to insert a
blk_mq_sched_mark_restart_hctx() call in a code path that is never triggered
by the NVMe driver. So I don't see how the change I proposed could affect
the performance of the NVMe driver?

Bart.