Re: [patch V3 10/11] x86/mm/cpa: Do the range check early

[Dave Hansen]

On 09/17/2018 07:29 AM, Thomas Gleixner wrote:
> To avoid excessive 4k wise checks in the common case do a quick check first
> whether the requested new page protections conflict with a static
> protection area in the large page. If there is no conflict then the
> decision whether to preserve or to split the page can be made immediately.
> 
> If the requested range covers the full large page, preserve it. Otherwise
> split it up. No point in doing a slow crawl in 4k steps.

That's the big one...

Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxx>