From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753081AbbCIHmT (ORCPT ); Mon, 9 Mar 2015 03:42:19 -0400 Received: from mail-ie0-f179.google.com ([209.85.223.179]:40134 "EHLO mail-ie0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752625AbbCIHmS (ORCPT ); Mon, 9 Mar 2015 03:42:18 -0400 Date: Mon, 9 Mar 2015 00:42:15 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andrew Morton cc: Naoya Horiguchi , Davidlohr Bueso , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [patch v2] mm, hugetlb: abort __get_user_pages if current has been oom killed In-Reply-To: <20150309043051.GA13380@node.dhcp.inet.fi> 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 be overcharged to its memcg since it has access to memory reserves or could potentially deplete all system 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: Naoya Horiguchi Cc: Davidlohr Bueso Cc: "Kirill A. Shutemov" Signed-off-by: David Rientjes --- v2: check signal inside follow_huegtlb_page() loop per Kirill 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.