Re: [RFC Patch] use MTRR for write combining if PAT is not available

[Ingo Molnar <mingo@elte.hu>]

* Thomas Schlichter <thomas.schlichter@web.de> wrote:

> Jan Beulich wrote:
>
> > Functionality-wise this looks fine to me; whether the core sysfs 
> > changes are acceptable I can't judge, though.
> 
> OK, I think I should have addressed your comments. Unfortunately I had 
> to use a little "hack" to make pci_mmap_page_range() work for sysfs 
> and proc. I placed a "private" pointer in the beginning of both 
> per-file private structures. So this pointer can be accessed 
> independent from the caller. I hope this is acceptable.
> 
> I dropped the ioremap() and set_memory_wc() patches, I could not 
> implement reference counting for them and it may interact too much 
> with existing GPU drivers.
> 
> Again, this series should not change the current behavior if either 
> MTRR is disabled or PAT is enabled. But it helps in the case that MTRR 
> is enabled and PAT is not available.
> 
> What should be done now to get this series on the right "track"?

Can we eliminate mtrr_add_unaligned() as Suresh suggested, and still 
make it work on your testbox?

Once that's done i'll look at putting it into the x86 tree for testing. 
The acks of Suresh/Venki/Jan would be nice to have.

	Ingo