From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f72.google.com (mail-lf0-f72.google.com [209.85.215.72]) by kanga.kvack.org (Postfix) with ESMTP id 85E0A6B03C0 for ; Thu, 20 Apr 2017 06:24:30 -0400 (EDT) Received: by mail-lf0-f72.google.com with SMTP id x8so8081265lfd.21 for ; Thu, 20 Apr 2017 03:24:30 -0700 (PDT) Received: from bes.se.axis.com (bes.se.axis.com. [195.60.68.10]) by mx.google.com with ESMTP id 143si3278197ljj.139.2017.04.20.03.24.28 for ; Thu, 20 Apr 2017 03:24:28 -0700 (PDT) From: Rabin Vincent Subject: [PATCH] mm: prevent NR_ISOLATE_* stats from going negative Date: Thu, 20 Apr 2017 12:24:25 +0200 Message-Id: <1492683865-27549-1-git-send-email-rabin.vincent@axis.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Rabin Vincent , Ming Ling , Michal Hocko , Minchan Kim , Vlastimil Babka , stable@vger.kernel.org From: Rabin Vincent Commit 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration") moved the dec_node_page_state() call (along with the page_is_file_cache() call) to after putback_lru_page(). But page_is_file_cache() can change after putback_lru_page() is called, so it should be called before putback_lru_page(), as it was before that patch, to prevent NR_ISOLATE_* stats from going negative. Without this fix, non-CONFIG_SMP kernels end up hanging in the while(too_many_isolated()) { congestion_wait() } loop in shrink_active_list() due to the negative stats. Mem-Info: active_anon:32567 inactive_anon:121 isolated_anon:1 active_file:6066 inactive_file:6639 isolated_file:4294967295 ^^^^^^^^^^ unevictable:0 dirty:115 writeback:0 unstable:0 slab_reclaimable:2086 slab_unreclaimable:3167 mapped:3398 shmem:18366 pagetables:1145 bounce:0 free:1798 free_pcp:13 free_cma:0 Fixes: 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration") Cc: Ming Ling Cc: Michal Hocko Cc: Minchan Kim Cc: Vlastimil Babka Cc: Signed-off-by: Rabin Vincent --- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/migrate.c b/mm/migrate.c index ed97c2c..738f1d5 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -184,9 +184,9 @@ void putback_movable_pages(struct list_head *l) unlock_page(page); put_page(page); } else { - putback_lru_page(page); dec_node_page_state(page, NR_ISOLATED_ANON + page_is_file_cache(page)); + putback_lru_page(page); } } } -- 2.7.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org