On Thu 14-12-17 18:25:54, Anshuman Khandual wrote: > On 12/14/2017 04:59 PM, Michal Hocko wrote: > > On Thu 14-12-17 16:44:26, Anshuman Khandual wrote: > >> diff --git a/mm/mprotect.c b/mm/mprotect.c > >> index ec39f73..43c29fa 100644 > >> --- a/mm/mprotect.c > >> +++ b/mm/mprotect.c > >> @@ -196,6 +196,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, > >> this_pages = change_pte_range(vma, pmd, addr, next, newprot, > >> dirty_accountable, prot_numa); > >> pages += this_pages; > >> + cond_resched(); > >> } while (pmd++, addr = next, addr != end); > >> > >> if (mni_start) > > > > this is not exactly what I meant. See how change_huge_pmd does continue. > > That's why I mentioned zap_pmd_range which does goto next... > > I might be still missing something but is this what you meant ? yes, except > Here we will give cond_resched() cover to the THP backed pages > as well. but there is still if (!is_swap_pmd(*pmd) && !pmd_trans_huge(*pmd) && !pmd_devmap(*pmd) && pmd_none_or_clear_bad(pmd)) continue; so we won't have scheduling point on pmd holes. Maybe this doesn't matter, I haven't checked but why should we handle those differently? > diff --git a/mm/mprotect.c b/mm/mprotect.c > index ec39f73..3d445ee 100644 > --- a/mm/mprotect.c > +++ b/mm/mprotect.c > @@ -188,7 +188,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, > } > > /* huge pmd was handled */ > - continue; > + goto next; > } > } > /* fall through, the trans huge pmd just split */ > @@ -196,6 +196,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, > this_pages = change_pte_range(vma, pmd, addr, next, newprot, > dirty_accountable, prot_numa); > pages += this_pages; > +next: > + cond_resched(); > } while (pmd++, addr = next, addr != end); > > if (mni_start) -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
