Commits
Aneesh Kumar K.V committed 346519a1606
powerpc/mm: Make sure a local_irq_disable prevent a parallel THP split We have generic code like the one in get_futex_key that assume that a local_irq_disable prevents a parallel THP split. Support that by adding a dummy smp call function after setting _PAGE_SPLITTING. Code paths like get_user_pages_fast still need to check for _PAGE_SPLITTING after disabling IRQ which indicate that a parallel THP splitting is ongoing. Now if they don't find _PAGE_SPLITTING set, then we can be sure that parallel split will now block in pmdp_splitting flush until we enables IRQ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>