Re: [PATCH RFC v2 12/24] hpsa: use reserved commands

Hannes Reinecke
2020-03-17T09:48:55Z

On 3/17/20 10:38 AM, John Garry wrote:
> On 11/03/2020 08:10, Ming Lei wrote:
>>> ands(struct ctlr_info *h)
>>> @@ -5803,6 +5803,7 @@ static int hpsa_scsi_host_alloc(struct
>>> ctlr_info *h)
>>>       sh->max_lun = HPSA_MAX_LUN;
>>>       sh->max_id = HPSA_MAX_LUN;
>>>       sh->can_queue = h->nr_cmds - HPSA_NRESERVED_CMDS;
>>> +    sh->nr_reserved_cmds = HPSA_NRESERVED_CMDS;
>> Now .nr_reserved_cmds has been passed to blk-mq, you need to increase
>> sh->can_queue to h->nr_cmds, because .can_queue is the whole queue depth
>> (include the part of reserved tags), otherwise, IO tags will be
>> decreased.
>>
>
> Sounds correct.
>
I will have having a look at the patchset; I thought I did a patch to
modify .can_queue so that it would cover only the usable tags, not the
reserved ones.

Cheers,

Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
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