From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f169.google.com (mail-ig0-f169.google.com [209.85.213.169]) by kanga.kvack.org (Postfix) with ESMTP id 54CFD6B0032 for ; Fri, 23 Jan 2015 10:17:47 -0500 (EST) Received: by mail-ig0-f169.google.com with SMTP id hl2so2657222igb.0 for ; Fri, 23 Jan 2015 07:17:47 -0800 (PST) Received: from resqmta-po-06v.sys.comcast.net (resqmta-po-06v.sys.comcast.net. [2001:558:fe16:19:96:114:154:165]) by mx.google.com with ESMTPS id 38si1310870iop.81.2015.01.23.07.17.46 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 23 Jan 2015 07:17:46 -0800 (PST) Date: Fri, 23 Jan 2015 09:17:44 -0600 (CST) From: Christoph Lameter Subject: Re: mmotm 2015-01-22-15-04: qemu failure due to 'mm: memcontrol: remove unnecessary soft limit tree node test' In-Reply-To: <20150123141817.GA22926@phnom.home.cmpxchg.org> Message-ID: References: <54c1822d.RtdGfWPekQVAw8Ly%akpm@linux-foundation.org> <20150123050802.GB22751@roeck-us.net> <20150123141817.GA22926@phnom.home.cmpxchg.org> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Guenter Roeck , 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, Stephen Rothwell , mhocko@suse.cz On Fri, 23 Jan 2015, Johannes Weiner wrote: > Is the assumption of this patch wrong? Does the specified node have > to be online for the fallback to work? Nodes that are offline have no control structures allocated and thus allocations will likely segfault when the address of the controls structure for the node is accessed. If we wanted to prevent that then every allocation would have to add a check to see if the nodes are online which would impact performance. -- 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