Messages in this thread | | | From | Bart Van Assche <> | Subject | Re: [RFC] blk-mq: clean up the hctx restart | Date | Thu, 2 Aug 2018 15:52:00 +0000 |
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On Wed, 2018-08-01 at 16:58 +0800, Ming Lei wrote: > On Wed, Aug 01, 2018 at 10:17:30AM +0800, jianchao.wang wrote: > > However, due to the limits in hctx_may_queue, q_b still cannot get the > > tags. The RR restart also will not wake up q_a. > > This is unfair for q_a. > > > > When we remove RR restart fashion, at least, the q_a will be waked up by > > the hctx restart. > > Is this the improvement of fairness you said in driver tag allocation ? > > I mean the fairness is totally covered by the general tag allocation > algorithm now, which is sort of FIFO style because of waitqueue, but RR > restart wakes up queue in the order of request queue.
From sbitmap.h:
#define SBQ_WAIT_QUEUES 8
What do you think is the effect of your patch if more than eight LUNs are active and the SCSI queue is full?
Thanks,
Bart.
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