On Sun, Nov 13, 2016 at 08:30:25PM +0530, Aneesh Kumar K.V wrote: > Add arch specific callback in the generic THP page cache code that will > deposit and withdarw preallocated page table. Archs like ppc64 use > this preallocated table to store the hash pte slot information. > > Testing: > kernel build of the patch series on tmpfs mounted with option huge=always > > The related thp stat: > thp_fault_alloc 72939 > thp_fault_fallback 60547 > thp_collapse_alloc 603 > thp_collapse_alloc_failed 0 > thp_file_alloc 253763 > thp_file_mapped 4251 > thp_split_page 51518 > thp_split_page_failed 1 > thp_deferred_split_page 73566 > thp_split_pmd 665 > thp_zero_page_alloc 3 > thp_zero_page_alloc_failed 0 > > Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
One nit-pick below, but otherwise Acked-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> > @@ -2975,6 +3004,13 @@ static int do_set_pmd(struct fault_env *fe, struct > page *page) > ret = 0; > count_vm_event(THP_FILE_MAPPED); > out: > + /* > + * If we are going to fallback to pte mapping, do a > + * withdraw with pmd lock held. > + */ > + if (arch_needs_pgtable_deposit() && (ret == VM_FAULT_FALLBACK)) Parenthesis are redundant around ret check. > + fe->prealloc_pte = pgtable_trans_huge_withdraw(vma->vm_mm, > + fe->pmd); > spin_unlock(fe->ptl); > return ret; > } -- Kirill A. Shutemov
