Hello, On Tue, Aug 04, 2015 at 03:09:37PM -0700, Andrew Morton wrote: > On Tue, 04 Aug 2015 19:40:08 +0900 Jaewon Kim <jaewon31.kim@xxxxxxxxxxx> wrote: > > > reclaim_clean_pages_from_list() assumes that shrink_page_list() returns > > number of pages removed from the candidate list. But shrink_page_list() > > puts back mlocked pages without passing it to caller and without > > counting as nr_reclaimed. This incurrs increasing nr_isolated. > > To fix this, this patch changes shrink_page_list() to pass unevictable > > pages back to caller. Caller will take care those pages. > > > > .. > > > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -1157,7 +1157,7 @@ cull_mlocked: > > if (PageSwapCache(page)) > > try_to_free_swap(page); > > unlock_page(page); > > - putback_lru_page(page); > > + list_add(&page->lru, &ret_pages); > > continue; > > > > activate_locked: > > Is this going to cause a whole bunch of mlocked pages to be migrated > whereas in current kernels they stay where they are? > It fixes two issues. 1. With unevictable page, cma_alloc will be successful. Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. 2. fix leaking of NR_ISOLATED counter of vmstat With it, too_many_isolated works. Otherwise, it could make hang until the process get SIGKILL. So, I think it's stable material. Acked-by: Minchan Kim <minchan@xxxxxxxxxx> -- 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>