Re: AGP PAT issue.

[Thomas Hellstrom <thomas@tungstengraphics.com>]

Rene Herman wrote:
> On 13-09-08 02:26, Pallipadi, Venkatesh wrote:
> 
>>>>> Haven't been subcribed to any lists recently and someone was 
>>>>> talking about "the other thread" before but just noticed that 
>>>>> an-rc6 was cut.
>>>>>
>>>>> Please note that the shutdown issue remains unfixed in it (I'm 
>>>>> doing my coalescing changes locally).
>>>>>
>>>> here's what is pending in tip/x86/pat for v2.6.28:
>>>>
>>> Only talking about .27 and just making sure again the issue is known.
>>>
>>> The above mentioned subject for the entry cache one ("fix Xorg 
>>> startup/shutdown slowdown with PAT") after all mistakingly says it 
>>> does something for shutdown.
>>>
>> Can you try the patch here 
>> http://www.ussg.iu.edu/hypermail/linux/kernel/0809.1/2074.html
>>
>> That should resolve both reserve and free issues..
> 
> Not for .27 though.
> 
> Rene.

Hi!
What's the status on this?

There are graphics devices we're working with that require large 
(non-AGP) write-combined memory buffers at any time.
We can solve the tlb- and cache flush latencies by using pools of these 
pages to allocate from and free to, but sooner or later we'll probably 
end up with _huge_ memtype lists. In the (very unlikely) worst case I 
guess they'd contain every other lowmem page in they system.

If I understand things correctly the patch above will fix this issue?
Will it be considered for future kernel inclusion.

Any enlightenment on this subject would be greatly appreciated.
Thanks,
/Thomas