From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754031AbaFXUQV (ORCPT ); Tue, 24 Jun 2014 16:16:21 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:59034 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753824AbaFXUQT (ORCPT ); Tue, 24 Jun 2014 16:16:19 -0400 Subject: [PATCH 3/3] mm: catch memory commitment underflow From: Konstantin Khlebnikov To: linux-mm@kvack.org, Andrew Morton Cc: Hugh Dickins , linux-kernel@vger.kernel.org Date: Wed, 25 Jun 2014 00:16:14 +0400 Message-ID: <20140624201614.18273.39034.stgit@zurg> In-Reply-To: <20140624201606.18273.44270.stgit@zurg> References: <20140624201606.18273.44270.stgit@zurg> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch prints warning (if CONFIG_DEBUG_VM=y) when memory commitment becomes too negative. Signed-off-by: Konstantin Khlebnikov --- mm/mmap.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/mmap.c b/mm/mmap.c index 129b847..d3decd9 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -134,6 +134,12 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) { unsigned long free, allowed, reserve; +#ifdef CONFIG_DEBUG_VM + WARN_ONCE(percpu_counter_read(&vm_committed_as) < + -(s64)vm_committed_as_batch * num_online_cpus(), + "memory commitment underflow"); +#endif + vm_acct_memory(pages); /*