From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 15 Mar 2018 18:07:47 +0300 Subject: [PATCH] mm/thp: Do not wait for lock_page() in deferred_split_scan() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit deferred_split_scan() gets called from reclaim path. Waiting for page lock may lead to deadlock there. Replace lock_page() with trylock_page() and skip the page if we failed to lock it. We will get to the page on the next scan. Fixes: 9a982250f773 ("thp: introduce deferred_split_huge_page()") Signed-off-by: Kirill A. Shutemov Acked-by: Michal Hocko (cherry-picked from https://patchwork.kernel.org/patch/10284703/) Signed-off-by: Fabian Grünbichler --- mm/huge_memory.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 8b887db33383..5c4093e0be8d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2621,11 +2621,13 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, list_for_each_safe(pos, next, &list) { page = list_entry((void *)pos, struct page, mapping); - lock_page(page); + if (!trylock_page(page)) + goto next; /* split_huge_page() removes page from list on success */ if (!split_huge_page(page)) split++; unlock_page(page); +next: put_page(page); } -- 2.14.2