[PATCH 1/3] drm/amdgpu: fix a typo

[Christian König]

Am 23.06.2017 um 11:08 schrieb zhoucm1:
>
>
> On 2017年06月23日 17:01, zhoucm1 wrote:
>>
>>
>> On 2017年06月23日 16:25, Christian König wrote:
>>> Am 23.06.2017 um 09:09 schrieb zhoucm1:
>>>>
>>>>
>>>> On 2017年06月23日 14:57, Christian König wrote:
>>>>> But giving the CS IOCTL an option for directly specifying the BOs 
>>>>> instead of a BO list like Marek suggested would indeed save us 
>>>>> some time here. 
>>>> interesting, I always follow how to improve our cs ioctl, since UMD 
>>>> guys aften complain our command submission is slower than windows.
>>>> Then how to directly specifying the BOs instead of a BO list? BO 
>>>> handle array from UMD? Could your guys describe more clear? Is it 
>>>> doable?
>>>
>>> Making the BO list part of the CS IOCTL wouldn't help at all for the 
>>> close source UMDs. To be precise we actually came up with the BO 
>>> list approach because of their requirement.
>>>
>>> The biggest bunch of work during CS is reserving all the buffers, 
>>> validating them and checking their VM status. 
>> Totally agree. Every time when I read code there, I often want to 
>> optimize them.
>>
>>> It doesn't matter if the BOs come from the BO list or directly in 
>>> the CS IOCTL.
>>>
>>> The key point is that CS overhead is pretty much irrelevant for the 
>>> open source stack, since Mesa does command submission from a 
>>> separate thread anyway.
>> If irrelevant for the open stack, then how does open source stack 
>> handle "The biggest bunch of work during CS is reserving all the 
>> buffers, validating them and checking their VM status."?

Command submission on the open stack is outsourced to a separate user 
space thread. E.g. when an application triggers a flush the IBs created 
so far are just put on a queue and another thread pushes them down to 
the kernel.

I mean reducing the overhead of the CS IOCTL is always nice, but you 
usual won't see any fps increase as long as not all CPUs are completely 
bound to some tasks.

>> If open stack has a better way, I think closed stack can follow it, I 
>> don't know the history.
> Do you not use bo list at all in mesa? radv as well?

I don't think so. Mesa just wants to send the list of used BOs down to 
the kernel with every IOCTL.

Regards,
Christian.

>
> Regards,
> David Zhou
>>
>> Regards,
>> David Zhou
>>>
>>> Regards,
>>> Christian.
>>>
>>>>
>>>> Regards,
>>>> David Zhou
>>>
>>>
>>
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>