[RFC PATCH] ARM: Assume new page cache pages have dirty D-cache

[Benjamin Herrenschmidt]

> As I just realised, this is going to subject all pages placed into
> userspace with a D cache flush - even anonymous pages, and those
> which we've been careful to deal with the cache issues already (eg,
> via the COW page copying code.)
> 
> I think all the copypage functions need to set PG_dcache_clean on the
> new pages once their copy has completed.
> 
> I wonder if there's any other anonymous page creating functions which
> could do with a similar treatment...

Do we do anything other than COW and zero page ? clear_user_page() I
suppose could deal with that if you do the cache bits there.

Cheers,
Ben.