Re: [Bug 10328] New: [regression] performance drop for glx

[Ingo Molnar]

* Suresh Siddha <suresh.b.siddha@xxxxxxxxx> wrote:

> fb drivers are using ioremap()/ioremap_nocache(), followed by mtrr_add 
> with WC attribute. Recent changes in page attribute code made both 
> ioremap()/ioremap_nocache() mappings as UC (instead of previous UC-). 
> This breaks the graphics performance, as the effective memory type is 
> UC instead of expected WC.
> 
> The correct way to fix this is to add ioremap_wc() (which uses UC- in 
> the absence of PAT kernel support and WC with PAT) and change all the 
> fb drivers to use this new ioremap_wc() API.
> 
> We can take this correct and longer route for post 2.6.25. For now, 
> revert back to the UC- behavior for ioremap/ioremap_nocache.

thanks Suresh, applied.

	Ingo
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