Re: [RFC 0/3] TTM priority queue logic

[Thomas Hellstrom <thellstrom@vmware.com>]

On 04/07/2014 04:39 PM, Lauri Kasanen wrote:
> On Mon, 07 Apr 2014 14:25:28 +0200
> Thomas Hellstrom <thellstrom@vmware.com> wrote:
>
>> Hi, Lauri.
>>
>> On 04/04/2014 03:52 PM, Lauri Kasanen wrote:
>>> Hi list, Thomas,
>>>
>>> I'd like to know if this is going in the right direction.
>> This looks fine with me.
>>
>> However, if possible I'd like the drivers to enable both alloc_threshold
>> and priority queue on a per-memory-type basis.
>>
>> That would mean no new arguments (use_pqueue, alloc_threshold) in
>> ttm_bo_device_init(). Instead, set default values in
>> ttm_bo_init_mm(), and let the driver change them in the init_mem_type()
>> callback.
>>
>> Do you think that would work?
> Thanks for the review.
>
> Alloc_threshold was removed, and the current patch (in drm-next)
> replaced it with a placement flag. So now that logic is in the driver.
>
> Making the pqueue a per-type option would certainly work, I'll edit it
> to do so. I don't see why it would improve GTT or SYSTEM given their
> perf characteristics, but I suppose future devices can always do weird
> things.

Yes. You don't have to explicitly check for VRAM, and drivers can also
set up
other fixed memory types, like a pre-allocated chunk of GTT.

Thanks,
Thomas


> - Lauri