From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 209AD6B004F for ; Tue, 30 Jun 2009 22:54:18 -0400 (EDT) Date: Wed, 1 Jul 2009 10:55:58 +0800 From: Shaohua Li Subject: Re: + memory-hotplug-alloc-page-from-other-node-in-memory-online.patch added to -mm tree Message-ID: <20090701025558.GA28524@sli10-desk.sh.intel.com> References: <200906291949.n5TJnuov028806@imap1.linux-foundation.org> <20090630004735.GA21254@sli10-desk.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090630004735.GA21254@sli10-desk.sh.intel.com> Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: "akpm@linux-foundation.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "mel@csn.ul.ie" , "Zhao, Yakui" List-ID: On Tue, Jun 30, 2009 at 08:47:35AM +0800, Shaohua Li wrote: > On Tue, Jun 30, 2009 at 06:07:16AM +0800, Christoph Lameter wrote: > > On Mon, 29 Jun 2009, akpm@linux-foundation.org wrote: > > > > > To initialize hotadded node, some pages are allocated. At that time, the > > > node hasn't memory, this makes the allocation always fail. In such case, > > > let's allocate pages from other nodes. > > > > Thats bad. Could you populate the buddy list with some large pages from > > the beginning of the node instead of doing this special casing? The > > vmemmap and other stuff really should come from the node that is added. > > Otherwise off node memory accesses will occur constantly for processors on > > that node. > Ok, this is preferred. But the node hasn't any memory present at that time, > let me check how could we do it. Hi Christoph, Looks this is quite hard. Memory of the node isn't added into buddy. At that time (sparse-vmmem init) buddy for the node isn't initialized and even page struct for the hotadded memory isn't prepared too. We need something like bootmem allocator to get memory ... -- 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