From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755480AbbAWQDm (ORCPT ); Fri, 23 Jan 2015 11:03:42 -0500 Received: from gum.cmpxchg.org ([85.214.110.215]:48958 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751464AbbAWQDj (ORCPT ); Fri, 23 Jan 2015 11:03:39 -0500 Date: Fri, 23 Jan 2015 11:03:35 -0500 From: Johannes Weiner To: Guenter Roeck Cc: akpm@linux-foundation.org, mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-next@vger.kernel.org, sfr@canb.auug.org.au, mhocko@suse.cz, cl@linux.com Subject: Re: mmotm 2015-01-22-15-04: qemu failure due to 'mm: memcontrol: remove unnecessary soft limit tree node test' Message-ID: <20150123160335.GB32592@phnom.home.cmpxchg.org> References: <54c1822d.RtdGfWPekQVAw8Ly%akpm@linux-foundation.org> <20150123050802.GB22751@roeck-us.net> <20150123141817.GA22926@phnom.home.cmpxchg.org> <54C26CE3.2060001@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54C26CE3.2060001@roeck-us.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 23, 2015 at 07:46:43AM -0800, Guenter Roeck wrote: > I added some debugging. First, the problem is only seen with SMP disabled. > Second, there is only one online node. > > Without your patch: > > Node 0 online 1 high 1 memory 1 cpu 0 normal 1 tmp 0 rtpn c00000003d240600 > Node 1 online 0 high 0 memory 0 cpu 0 normal 0 tmp -1 rtpn c00000003d240640 > Node 2 online 0 high 0 memory 0 cpu 0 normal 0 tmp -1 rtpn c00000003d240680 > > [ and so on up to node 255 ] > > With your patch: > > Node 0 online 1 high 1 memory 1 cpu 0 normal 1 rtpn c00000003d240600 > Unable to handle kernel paging request for data at address 0x0000af50 > Faulting instruction address: 0xc000000000895a3c > Oops: Kernel access of bad area, sig: 11 [#1] > > The log message is after the call to kzalloc_node. > > So it doesn't look like the fallback is working, at least not with ppc64 > in non-SMP mode. Yep, and Christoph confirmed that it's not meant to work like that. The patch is flawed. Thanks for testing and sorry for breaking your setup. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f49.google.com (mail-wg0-f49.google.com [74.125.82.49]) by kanga.kvack.org (Postfix) with ESMTP id 1B4526B0032 for ; Fri, 23 Jan 2015 11:03:42 -0500 (EST) Received: by mail-wg0-f49.google.com with SMTP id k14so3893707wgh.8 for ; Fri, 23 Jan 2015 08:03:41 -0800 (PST) Received: from gum.cmpxchg.org (gum.cmpxchg.org. [85.214.110.215]) by mx.google.com with ESMTPS id hh5si3270948wib.88.2015.01.23.08.03.40 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Jan 2015 08:03:40 -0800 (PST) Date: Fri, 23 Jan 2015 11:03:35 -0500 From: Johannes Weiner Subject: Re: mmotm 2015-01-22-15-04: qemu failure due to 'mm: memcontrol: remove unnecessary soft limit tree node test' Message-ID: <20150123160335.GB32592@phnom.home.cmpxchg.org> References: <54c1822d.RtdGfWPekQVAw8Ly%akpm@linux-foundation.org> <20150123050802.GB22751@roeck-us.net> <20150123141817.GA22926@phnom.home.cmpxchg.org> <54C26CE3.2060001@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54C26CE3.2060001@roeck-us.net> Sender: owner-linux-mm@kvack.org List-ID: To: Guenter Roeck Cc: akpm@linux-foundation.org, mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-next@vger.kernel.org, sfr@canb.auug.org.au, mhocko@suse.cz, cl@linux.com On Fri, Jan 23, 2015 at 07:46:43AM -0800, Guenter Roeck wrote: > I added some debugging. First, the problem is only seen with SMP disabled. > Second, there is only one online node. > > Without your patch: > > Node 0 online 1 high 1 memory 1 cpu 0 normal 1 tmp 0 rtpn c00000003d240600 > Node 1 online 0 high 0 memory 0 cpu 0 normal 0 tmp -1 rtpn c00000003d240640 > Node 2 online 0 high 0 memory 0 cpu 0 normal 0 tmp -1 rtpn c00000003d240680 > > [ and so on up to node 255 ] > > With your patch: > > Node 0 online 1 high 1 memory 1 cpu 0 normal 1 rtpn c00000003d240600 > Unable to handle kernel paging request for data at address 0x0000af50 > Faulting instruction address: 0xc000000000895a3c > Oops: Kernel access of bad area, sig: 11 [#1] > > The log message is after the call to kzalloc_node. > > So it doesn't look like the fallback is working, at least not with ppc64 > in non-SMP mode. Yep, and Christoph confirmed that it's not meant to work like that. The patch is flawed. Thanks for testing and sorry for breaking your setup. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org