Benjamin Herrenschmidt [off-list ref] writes:

On Tue, 2014-07-29 at 12:25 +0530, Aneesh Kumar K.V wrote:

quoted

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).

The reace against withdraw is not a real problem. We use
get_hpte_slot_array in huge page invalidate and hash page. In the first
case we are holding pmd_trans_huge_lock and in the later we have the
_PAGE_BUSY check.

-aneesh