On Fri, Oct 18, 2019 at 01:48:32PM +0200, Michal Hocko wrote: > On Thu 17-10-19 16:21:08, Oscar Salvador wrote: > > From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> > > > > Drop the PageHuge check since memory_failure forks into memory_failure_hugetlb() > > for hugetlb pages. > > > > Signed-off-by: Oscar Salvador <osalvador@xxxxxxx> > > Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> > > s-o-b chain is reversed. > > The code is a bit confusing. Doesn't this check aim for THP? No, PageHuge() is false for thp, so this if branch is just dead code. > AFAICS > PageTransHuge(hpage) will split the THP or fail so PageTransHuge > shouldn't be possible anymore, right? Yes, that's right. > But why does hwpoison_user_mappings > still work with hpage then? hwpoison_user_mappings() is called both from memory_failure() and from memory_failure_hugetlb(), so it need handle both cases. Thanks, Naoya Horiguchi > > > --- > > mm/memory-failure.c | 5 +---- > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > > index 05c8c6df25e6..2cbadb58c7df 100644 > > --- a/mm/memory-failure.c > > +++ b/mm/memory-failure.c > > @@ -1345,10 +1345,7 @@ int memory_failure(unsigned long pfn, int flags) > > * page_remove_rmap() in try_to_unmap_one(). So to determine page status > > * correctly, we save a copy of the page flags at this time. > > */ > > - if (PageHuge(p)) > > - page_flags = hpage->flags; > > - else > > - page_flags = p->flags; > > + page_flags = p->flags; > > > > /* > > * unpoison always clear PG_hwpoison inside page lock > > -- > > 2.12.3 > > -- > Michal Hocko > SUSE Labs >
