On 11/08/2016 05:01 AM, Naoya Horiguchi wrote: > This patch prepares thp migration's core code. These code will be open when > unmap_and_move() stops unconditionally splitting thp and get_new_page() starts > to allocate destination thps. >
Snip > Signed-off-by: Naoya Horiguchi <[email protected]> > --- > ChangeLog v1 -> v2: > - support pte-mapped thp, doubly-mapped thp > --- > arch/x86/include/asm/pgtable_64.h | 2 + > include/linux/swapops.h | 61 +++++++++++++++ > mm/huge_memory.c | 154 > ++++++++++++++++++++++++++++++++++++++ > mm/migrate.c | 44 ++++++++++- > mm/pgtable-generic.c | 3 +- > 5 files changed, 262 insertions(+), 2 deletions(-) > diff --git v4.9-rc2-mmotm-2016-10-27-18-27/mm/pgtable-generic.c > v4.9-rc2-mmotm-2016-10-27-18-27_patched/mm/pgtable-generic.c > index 71c5f91..6012343 100644 > --- v4.9-rc2-mmotm-2016-10-27-18-27/mm/pgtable-generic.c > +++ v4.9-rc2-mmotm-2016-10-27-18-27_patched/mm/pgtable-generic.c > @@ -118,7 +118,8 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, > unsigned long address, > { > pmd_t pmd; > VM_BUG_ON(address & ~HPAGE_PMD_MASK); > - VM_BUG_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp)); > + VM_BUG_ON(pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) && > + !pmd_devmap(*pmdp)) Its a valid VM_BUG_ON check but is it related to THP migration or just a regular fix up ?
