Re: [PATCH 13/14] scsi: add support for a blk-mq based I/O path.

From: Kashyap Desai
Date: Tue Aug 19 2014 - 12:11:08 EST


On Tue, Aug 19, 2014 at 9:36 PM, Christoph Hellwig <hch@xxxxxx> wrote:
> On Tue, Aug 19, 2014 at 03:51:42AM +0530, Kashyap Desai wrote:
>> I read this comment and find that very few drivers are using this
>> cmd_list. I think if we remove this cmd_list, performance will scale as I
>> am seeing major contention in this lock.
>> Just thought to ping you to see if this is known limitation for now or any
>> plan to change this lock in near future ?
>
> Removing the lock entirely and pushing the list into the two drivers
> using it is on my TODO list. Bart actually suggested keeping the code in the
> SCSI core and having a flag to enabled. Given that I'm too busy to get my full
> version done in time, it might be a good idea if someone picks up Barts
> idea. Can you send me a patch to add a enable_cmd_list flag to the host
> template and only enable it for aacraid and dpt_i2o?
>

Sure. I will work on relevant code change and will post patch for review.

--
Device Driver Developer @ Avagotech
Kashyap D. Desai
Note - my new email address
kashyap.desai@xxxxxxxxxxxxx
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