From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757196Ab3BAQ6C (ORCPT ); Fri, 1 Feb 2013 11:58:02 -0500 Received: from terminus.zytor.com ([198.137.202.10]:58405 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756871Ab3BAQ6A (ORCPT ); Fri, 1 Feb 2013 11:58:00 -0500 Message-ID: <510BF3F1.2050605@zytor.com> Date: Fri, 01 Feb 2013 08:57:21 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Pavel Machek CC: Phil Turmel , paul.szabo@sydney.edu.au, ben@decadent.org.uk, dave@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: PAE problems was [RFC] Reproducible OOM with just a few sleeps References: <201302010313.r113DTj3027195@como.maths.usyd.edu.au> <510B46C3.5040505@turmel.org> <20130201102044.GA2801@amd.pavel.ucw.cz> <20130201102545.GA3053@amd.pavel.ucw.cz> In-Reply-To: <20130201102545.GA3053@amd.pavel.ucw.cz> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/01/2013 02:25 AM, Pavel Machek wrote: > > On Fri 2013-02-01 11:20:44, Pavel Machek wrote: >> On Thu 2013-01-31 23:38:27, Phil Turmel wrote: >>> On 01/31/2013 10:13 PM, paul.szabo@sydney.edu.au wrote: >>>> [trim /] Does not that prove that PAE is broken? >>> >>> Please, Paul, take *yes* for an answer. It is broken. You've received >>> multiple dissertations on why it is going to stay that way. Unless you >>> fix it yourself, and everyone seems to be politely wishing you the best >>> of luck with that. >> >> It is not Paul's job to fix PAE. It is job of whoever broke it to do >> so. >> >> If it is broken with 2GB of RAM, it is clearly not the known "lowmem >> starvation" issue, it is something else... and probably worth >> debugging. >> >> So, Paul, if you have time and interest... Try to find some old kernel >> version where sleep test works with PAE. Hopefully there is one. Then >> do bisection... author of the patch should then fix it. (And if not, >> at least you have patch you can revert.) >> >> rjw is worth cc-ing at that point. > > Ouch, and... IIRC (hpa should know for sure), PAE is neccessary for > R^X support on x86, thus getting more common, not less. If it does not > work, that's bad news. > > Actually, if PAE is known broken, it should probably get marked as > such in Kconfig. That's sure to get some discussion started... > Pavel > OK, so by the time this thread gets to me there is of course no information in it. The vast majority of all 32-bit kernels compiled these days are PAE, so it would seem rather odd if PAE was totally broken. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.