On Tue, Jul 15, 2014 at 06:07:35PM +0200, Michal Hocko wrote: > On Tue 15-07-14 11:55:37, Naoya Horiguchi wrote: > > On Wed, Jun 18, 2014 at 04:40:45PM -0400, Johannes Weiner wrote: > > ... > > > diff --git a/mm/swap.c b/mm/swap.c > > > index a98f48626359..3074210f245d 100644 > > > --- a/mm/swap.c > > > +++ b/mm/swap.c > > > @@ -62,6 +62,7 @@ static void __page_cache_release(struct page *page) > > > del_page_from_lru_list(page, lruvec, page_off_lru(page)); > > > spin_unlock_irqrestore(&zone->lru_lock, flags); > > > } > > > + mem_cgroup_uncharge(page); > > > } > > > > > > static void __put_single_page(struct page *page) > > > > This seems to cause a list breakage in hstate->hugepage_activelist > > when freeing a hugetlbfs page. > > This looks like a fall out from > http://marc.info/?l=linux-mm&m=140475936311294&w=2 > > I didn't get to review this one but the easiest fix seems to be check > HugePage and do not call uncharge. Yes, that makes sense. I'm also moving the uncharge call into __put_single_page() and __put_compound_page() so that PageHuge(), a function call, only needs to be checked for compound pages. > > For hugetlbfs, we uncharge in free_huge_page() which is called after > > __page_cache_release(), so I think that we don't have to uncharge here. > > > > In my testing, moving mem_cgroup_uncharge() inside if (PageLRU) block > > fixed the problem, so if that works for you, could you fold the change > > into your patch? Memcg pages that *do* need uncharging might not necessarily be on the LRU list. Does the following work for you? Thanks! --- diff --git a/mm/swap.c b/mm/swap.c index 3461f2f5be20..af5c8ad830d1 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -62,12 +62,12 @@ static void __page_cache_release(struct page *page) del_page_from_lru_list(page, lruvec, page_off_lru(page)); spin_unlock_irqrestore(&zone->lru_lock, flags); } - mem_cgroup_uncharge(page); } static void __put_single_page(struct page *page) { __page_cache_release(page); + mem_cgroup_uncharge(page); free_hot_cold_page(page, false); } @@ -76,6 +76,8 @@ static void __put_compound_page(struct page *page) compound_page_dtor *dtor; __page_cache_release(page); + if (!PageHuge(page)) + mem_cgroup_uncharge(page); dtor = get_compound_page_dtor(page); (*dtor)(page); } -- 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>