From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753566AbbCIUHq (ORCPT ); Mon, 9 Mar 2015 16:07:46 -0400 Received: from mail-ie0-f172.google.com ([209.85.223.172]:42390 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752528AbbCIUHm (ORCPT ); Mon, 9 Mar 2015 16:07:42 -0400 Date: Mon, 9 Mar 2015 13:07:39 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andrew Morton cc: Greg Thelen , Naoya Horiguchi , Davidlohr Bueso , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [patch v3] mm, hugetlb: abort __get_user_pages if current has been oom killed In-Reply-To: Message-ID: References: <20150309043051.GA13380@node.dhcp.inet.fi> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If __get_user_pages() is faulting a significant number of hugetlb pages, usually as the result of mmap(MAP_LOCKED), it can potentially allocate a very large amount of memory. If the process has been oom killed, this will cause a lot of memory to potentially deplete memory reserves. In the same way that commit 4779280d1ea4 ("mm: make get_user_pages() interruptible") aborted for pending SIGKILLs when faulting non-hugetlb memory, based on the premise of commit 462e00cc7151 ("oom: stop allocating user memory if TIF_MEMDIE is set"), hugetlb page faults now terminate when the process has been oom killed. Cc: Greg Thelen Cc: Naoya Horiguchi Cc: Davidlohr Bueso Acked-by: "Kirill A. Shutemov" Signed-off-by: David Rientjes --- v3: tweak changelog per Greg mm/hugetlb.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3276,6 +3276,15 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page *page; /* + * If we have a pending SIGKILL, don't keep faulting pages and + * potentially allocating memory. + */ + if (unlikely(fatal_signal_pending(current))) { + remainder = 0; + break; + } + + /* * Some archs (sparc64, sh*) have multiple pte_ts to * each hugepage. We have to make sure we get the * first, for the page indexing below to work.