Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161081AbWBYTwM (ORCPT ); Sat, 25 Feb 2006 14:52:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161091AbWBYTwM (ORCPT ); Sat, 25 Feb 2006 14:52:12 -0500 Received: from fw5.argo.co.il ([194.90.79.130]:33296 "EHLO argo2k.argo.co.il") by vger.kernel.org with ESMTP id S1161081AbWBYTwL (ORCPT ); Sat, 25 Feb 2006 14:52:11 -0500 Message-ID: <4400B562.6020203@argo.co.il> Date: Sat, 25 Feb 2006 21:52:02 +0200 From: Avi Kivity User-Agent: Mozilla Thunderbird 1.0.7-1.1.fc4 (X11/20050929) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Jesper Juhl CC: Victor Porton , linux-kernel@vger.kernel.org Subject: Re: New reliability technique References: <9a8748490602250526p2187e04ej9a680e6b2b948e7d@mail.gmail.com> <9a8748490602250527l78e057ecvcd2e656b8ff5c9f2@mail.gmail.com> In-Reply-To: <9a8748490602250527l78e057ecvcd2e656b8ff5c9f2@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 25 Feb 2006 19:52:08.0128 (UTC) FILETIME=[F5B7AC00:01C63A44] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1606 Lines: 48 Jesper Juhl wrote: >On 2/25/06, Jesper Juhl wrote: > > >>On 2/25/06, Victor Porton wrote: >> >> >>>A minute ago I invented a new reliability enhancing technique. >>> >>>In idle cycles (or periodically in expense of some performance) Linux can >>>calculate MD5 or CRC sums of _unused_ (free) memory areas and compare these >>>sums with previously calculated sums. >>> >>>Additionally it can be done for allocated memory, if it will be write >>>protected before the first actual write. Moreover, all memory may be made >>>write-protected if it is not written e.g. more than a second. (When it >>>is written kernel would unlock it and allow to write, by a techniqie like >>>to how swap works.) If write-protected memory appears to be modified by >>>a check sum, this likewise indicates a bug. >>> >>>If a sum is inequal, it would notice a bug in kernel or in hardware. >>> >>>I suggest to add "Check free memory control sums" in config. >>> >>> >>> >>Implement it then and send a patch. >> >> >> > >But, doesn't slab poisoning and the like already cover this ground somewhat? > > > No, they don't. They cover only a very small percentage of memory. On the other hand, ECC memory and caches do this in hardware. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. - 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/