On Thu, Jun 25, 2015 at 5:24 PM, Alex Elder <elder@xxxxxxxx> wrote:
> On 06/25/2015 04:11 AM, Ilya Dryomov wrote:
>>
>> nr_requests (/sys/block/rbd<id>/queue/nr_requests) is pretty much
>> irrelevant in blk-mq case because each driver sets its own max depth
>> that it can handle and that's the number of tags that gets preallocated
>> on setup. Users can't increase queue depth beyond that value via
>> writing to nr_requests.
>>
>> For rbd we are happy with the default BLKDEV_MAX_RQ (128) for most
>> cases but we want to give users the opportunity to increase it.
>> Introduce a new per-device queue_depth option to do just that:
>>
>> $ sudo rbd map -o queue_depth=1024 ...
>>
>> Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
>
>
> I haven't gone to follow through what happens with this
> but I assume a value that's too large will be caught when
> it's attempted to be used or something.
>
> In any case this looks good to me.
>
> Reviewed-by: Alex Elder <elder@xxxxxxxxxx>
Yeah, blk-mq core will cap it at BLK_MQ_MAX_DEPTH (10240).
Thanks for the review,
Ilya
--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
