[PATCH] powerpc: thp: Add write barrier after updating the valid bit

[Benjamin Herrenschmidt]

On Tue, 2014-07-29 at 12:25 +0530, Aneesh Kumar K.V wrote:
> We want to make sure for usage like below we don't reorder the  load.
> 
> if (pmd_trans_huge(*pmdp)){
> 
>    get_hpte_slot_array(pmdp)
> }

Shouldn't we also make sure that we don't have lock set ? (In case it's
in the middle of being updated).

Cheers,
Ben.