From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757948AbZEVO6v (ORCPT ); Fri, 22 May 2009 10:58:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757073AbZEVO6o (ORCPT ); Fri, 22 May 2009 10:58:44 -0400 Received: from smtp3.ultrahosting.com ([74.213.175.254]:45098 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754798AbZEVO6n (ORCPT ); Fri, 22 May 2009 10:58:43 -0400 Date: Fri, 22 May 2009 10:17:15 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@qirst.com To: Pavel Machek cc: Dave Hansen , David Rientjes , Andrew Morton , Greg Kroah-Hartman , Nick Piggin , Mel Gorman , Peter Ziljstra , San Mehat , Arve Hj?nnev?g , linux-kernel@vger.kernel.org Subject: Warn when we run out of swap space (was Re: Misleading OOM messages) In-Reply-To: Message-ID: References: <1242333519.15391.210.camel@nimitz> <1242335120.15391.242.camel@nimitz> <20090514213403.GB14741@elf.ucw.cz> <1242337299.28440.47.camel@nimitz> <20090515130547.GA1976@elf.ucw.cz> <20090515200213.GA1406@ucw.cz> <20090519203944.GD1362@ucw.cz> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) 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 Subject: Warn if we run out of swap space Running out of swap space means that the evicton of anonymous pages may no longer be possible which can lead to OOM conditions. Print a warning when swap space first becomes exhausted. Signed-off-by: Christoph Lameter --- mm/swapfile.c | 1 + 1 file changed, 1 insertion(+) Index: linux-2.6/mm/swapfile.c =================================================================== --- linux-2.6.orig/mm/swapfile.c 2009-05-22 09:07:40.000000000 -0500 +++ linux-2.6/mm/swapfile.c 2009-05-22 09:15:59.000000000 -0500 @@ -412,6 +412,7 @@ swp_entry_t get_swap_page(void) nr_swap_pages++; noswap: spin_unlock(&swap_lock); + WARN_ONCE(1, "All of swap is in use. Some pages cannot be swapped out."); return (swp_entry_t) {0}; }