From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 8E7B16B004D for ; Tue, 2 Mar 2010 16:17:14 -0500 (EST) Received: from spaceape8.eur.corp.google.com (spaceape8.eur.corp.google.com [172.28.16.142]) by smtp-out.google.com with ESMTP id o22LH8ro008821 for ; Tue, 2 Mar 2010 21:17:08 GMT Received: from pwi5 (pwi5.prod.google.com [10.241.219.5]) by spaceape8.eur.corp.google.com with ESMTP id o22LH6DV007833 for ; Tue, 2 Mar 2010 13:17:07 -0800 Received: by pwi5 with SMTP id 5so386375pwi.6 for ; Tue, 02 Mar 2010 13:17:05 -0800 (PST) Date: Tue, 2 Mar 2010 13:17:03 -0800 (PST) From: David Rientjes Subject: Re: [patch] slab: add memory hotplug support In-Reply-To: <20100302125306.GD19208@basil.fritz.box> Message-ID: References: <4B862623.5090608@cs.helsinki.fi> <20100226114136.GA16335@basil.fritz.box> <20100226155755.GE16335@basil.fritz.box> <20100302125306.GD19208@basil.fritz.box> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Andi Kleen Cc: Pekka Enberg , Nick Piggin , Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org, haicheng.li@intel.com, KAMEZAWA Hiroyuki List-ID: On Tue, 2 Mar 2010, Andi Kleen wrote: > The patch looks far more complicated than my simple fix. > > Is more complicated now better? > If you still believe these are "fixes," then perhaps you don't fully understand the issue: slab completely lacked memory hotplug support when a node is either being onlined or offlined that do not have hotadded or hotremoved cpus. It's as simple as that. To be fair, my patch may appear more complex because it implements full memory hotplug support so that the nodelists are properly drained and freed when the same memory regions you onlined for memory hot-add are now offlined. Notice, also, how it touches no other slab code as implementing new support for something shouldn't. There is no need for additional hacks to be added in other slab code if you properly allocate and initialize the nodelists for the memory being added before it is available for use by the kernel. If you'd test my patch out on your setup, that would be very helpful. I can address any additional issues that you may undercover if you post the oops while doing either memory online or offline. -- 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