arch/tile: fix up locking in pgtable.c slightly
We should be holding the init_mm.page_table_lock in shatter_huge_page()
since we are modifying the kernel page tables. Then, only if we are
walking the other root page tables to update them, do we want to take
the pgd_lock.
Add a comment about taking the pgd_lock that we always do it with
interrupts disabled and therefore are not at risk from the tlbflush
IPI deadlock as is seen on x86.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
1 file changed