Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759398AbZGAC4I (ORCPT ); Tue, 30 Jun 2009 22:56:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755266AbZGACz5 (ORCPT ); Tue, 30 Jun 2009 22:55:57 -0400 Received: from mga01.intel.com ([192.55.52.88]:16252 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754654AbZGACz4 (ORCPT ); Tue, 30 Jun 2009 22:55:56 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.42,320,1243839600"; d="scan'208";a="471035095" Date: Wed, 1 Jul 2009 10:55:58 +0800 From: Shaohua Li To: Christoph Lameter Cc: "akpm@linux-foundation.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "mel@csn.ul.ie" , "Zhao, Yakui" 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> 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 Content-Length: 1356 Lines: 25 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/