Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161093AbWBYT43 (ORCPT ); Sat, 25 Feb 2006 14:56:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161094AbWBYT43 (ORCPT ); Sat, 25 Feb 2006 14:56:29 -0500 Received: from zproxy.gmail.com ([64.233.162.198]:47750 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S1161093AbWBYT43 convert rfc822-to-8bit (ORCPT ); Sat, 25 Feb 2006 14:56:29 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=nh3JKu7mGsfwXr5z3FzOQ/9uXCy1U4STIJOl1291OcXffLYzqwUR2xVtB4pa05X61ajRpQTd2QxZslqBzbvhXV0yczjK+kdXgSzu4HFVVTuiCf3vbNxJ4f89CQ218IWMO5NpHv16RJxcJwBLA/YY/wTNQTWz2W1g693ZSSiGzuo= Message-ID: <9a8748490602251156y6dc22a7by53b85570feb8d4a7@mail.gmail.com> Date: Sat, 25 Feb 2006 20:56:27 +0100 From: "Jesper Juhl" To: "Avi Kivity" Subject: Re: New reliability technique Cc: "Victor Porton" , linux-kernel@vger.kernel.org In-Reply-To: <4400B562.6020203@argo.co.il> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <9a8748490602250526p2187e04ej9a680e6b2b948e7d@mail.gmail.com> <9a8748490602250527l78e057ecvcd2e656b8ff5c9f2@mail.gmail.com> <4400B562.6020203@argo.co.il> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1819 Lines: 53 On 2/25/06, Avi Kivity wrote: > 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. > Ohh, ok, then it makes sense as a debug thing. Let's see an implementation then. -- Jesper Juhl Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html - 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/