From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755949AbYKKMvR (ORCPT ); Tue, 11 Nov 2008 07:51:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756647AbYKKMut (ORCPT ); Tue, 11 Nov 2008 07:50:49 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:56609 "EHLO gprs189-60.eurotel.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755765AbYKKMus (ORCPT ); Tue, 11 Nov 2008 07:50:48 -0500 Date: Tue, 11 Nov 2008 11:30:43 +0100 From: Pavel Machek To: "Rafael J. Wysocki" Cc: Andi Kleen , Ingo Molnar , kernel list , "H. Peter Anvin" Subject: Re: CONFIG_NUMA breaks hibernation on x86-32 with PAE Message-ID: <20081111103043.GD5464@elf.ucw.cz> References: <20081109140726.GB1786@ucw.cz> <20081110080436.GF2093@elte.hu> <87hc6fpwof.fsf@basil.nowhere.org> <200811101928.04565.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200811101928.04565.rjw@sisk.pl> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 2008-11-10 19:28:03, Rafael J. Wysocki wrote: > On Monday, 10 of November 2008, Andi Kleen wrote: > > Ingo Molnar writes: > > > > > > No good ideas - the bug description gives me the impression of memory > > > maps save/restore hickup in the hibernation code - and memory maps are > > > pretty much the only thing that are significantly different on NUMA. > > > > I assume the problem happened on a single node system. > > On single node the memory map should be actually quite similar > > to the UMA case. > > It is. However, the problem is 100% reproducible on any 32-bit single-node > system with CONFIG_NUMA set, from what I can tell. > > It doesn't happen if the kernel is booted with highmem=0, so it looks like > the code that saves highmem causes the problem to happen. However, this > same code works well for all of the !CONFIG_NUMA cases and practically only > the only non-open-coded it uses is kmap_atomic(). kmap_atomic() and kernel_map_pages(), AFAICT. Can kmap_atomic() modify pages in highmem, too? Wait... are we putting kernel pagetables in the high memory? What about this cleanup (warning: untested) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 5d2ab83..f1d8336 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -966,7 +966,7 @@ static void copy_data_page(unsigned long * data modified by kmap_atomic() */ safe_copy_page(buffer, s_page); - dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0); + dst = kmap_atomic(d_page, KM_USER0); memcpy(dst, buffer, PAGE_SIZE); kunmap_atomic(dst, KM_USER0); } else { Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html