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.
