From 0c0844f9fa0bc72019ce2b481ef586db4d8566a3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 14 Jul 2016 17:55:21 -0400 Subject: [PATCH] 4.1.28 Fix bad backport of 8f182270dfec "mm/swap.c: flush lru pvecs on compound page arrival" When I pulled in 4.1.28 into my stable 4.1-rt tree and ran the tests, it crashed with a severe OOM killing everything. I then tested 4.1.28 without -rt and it had the same issue. I did a bisect between 4.1.27 and 4.1.28 and found that the bug started at: commit 8f182270dfec "mm/swap.c: flush lru pvecs on compound page arrival" Looking at that patch and what's in mainline, I see that there's a mismatch in one of the hunks: Mainline: @@ -391,9 +391,8 @@ static void __lru_cache_add(struct page *page) struct pagevec *pvec = &get_cpu_var(lru_add_pvec); get_page(page); - if (!pagevec_space(pvec)) + if (!pagevec_add(pvec, page) || PageCompound(page)) __pagevec_lru_add(pvec); - pagevec_add(pvec, page); put_cpu_var(lru_add_pvec); } Stable 4.1.28: @@ -631,9 +631,8 @@ static void __lru_cache_add(struct page *page) struct pagevec *pvec = &get_cpu_var(lru_add_pvec); page_cache_get(page); - if (!pagevec_space(pvec)) + if (!pagevec_space(pvec) || PageCompound(page)) __pagevec_lru_add(pvec); - pagevec_add(pvec, page); put_cpu_var(lru_add_pvec); } Where mainline replace pagevec_space() with pagevec_add, and stable did not. Fixing this makes the OOM go away. Note, 3.18 has the same bug. Signed-off-by: Steven Rostedt Signed-off-by: Sasha Levin Signed-off-by: Otavio Salvador --- mm/swap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/swap.c b/mm/swap.c index b523f0a4cbfb..ab3b9c2dd783 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -631,7 +631,7 @@ static void __lru_cache_add(struct page *page) struct pagevec *pvec = &get_cpu_var(lru_add_pvec); page_cache_get(page); - if (!pagevec_space(pvec) || PageCompound(page)) + if (!pagevec_add(pvec, page) || PageCompound(page)) __pagevec_lru_add(pvec); put_cpu_var(lru_add_pvec); }