Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756919Ab1EKXIE (ORCPT ); Wed, 11 May 2011 19:08:04 -0400 Received: from mga01.intel.com ([192.55.52.88]:7472 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753402Ab1EKXIB (ORCPT ); Wed, 11 May 2011 19:08:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,354,1301900400"; d="scan'208";a="1091436" From: Andi Kleen To: Andrew Lutomirski Cc: linux-kernel@vger.kernel.org Subject: Re: Kernel falls apart under light memory pressure (i.e. linking vmlinux) References: Date: Wed, 11 May 2011 16:07:40 -0700 In-Reply-To: (Andrew Lutomirski's message of "Wed, 11 May 2011 18:42:38 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) 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 Content-Length: 1626 Lines: 40 Andrew Lutomirski writes: > > I can sometimes (but not always) trigger this by enabling swap and > running dirty_ram 2048 (attached). (One time it took the system down > completely. I have ~8 GB of swap, all of which was empty when I ran Never configure that much swap (> 1*RAM). It will just make any OOM more painful because it'll thrash forever. If you're 4x overcommited no workload will be happy. > This box is a Lenovo X220 Sandy Bridge laptop with 2G of RAM (the old > box had more) and runs ext4 on LVM on dm-crypt on an SSD. I see the FWIW i had problems in swapping over dmcrypt for a long time -- not quite as severe as you. Never really tracked it down. But I suspect just not doing the swap over dmcrypt would make it a lot more usable. > If I had to guess, I'd say that the VM gets confused when it's forced > to write data out to my LVM-over-dm-crypt partition and either starts > OOM-killing things when it's not out of memory or deadlocks because it > runs out of available RAM and can't service new dm-crypt and block > requests. > > Please help fix/debug this. It's making my shiny new laptop almost useless. I would add some tracing to the dmcrypt paths and then log it over the network during the problem. Most likely some part of it stalls or tries to allocate more memory. -Andi -- ak@linux.intel.com -- Speaking for myself only -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/