tree 08fc6a29a0430599b9e91e9e87945b0b6eb2ef6a
parent 5f220704127ae70db519fabbda4ece649eadac7f
author Chris Metcalf <cmetcalf@tilera.com> 1333050608 -0400
committer Chris Metcalf <cmetcalf@tilera.com> 1333383202 -0400

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>