Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757756AbZGCPkj (ORCPT ); Fri, 3 Jul 2009 11:40:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758004AbZGCPkX (ORCPT ); Fri, 3 Jul 2009 11:40:23 -0400 Received: from hera.kernel.org ([140.211.167.34]:58761 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757761AbZGCPkV (ORCPT ); Fri, 3 Jul 2009 11:40:21 -0400 Message-ID: <4A4E2638.9080101@kernel.org> Date: Fri, 03 Jul 2009 08:39:36 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Christoph Lameter CC: alex.shi@intel.com, Andrew Morton , Ingo Molnar , "bugzilla-daemon@bugzilla.kernel.org" , "bugme-daemon@bugzilla.kernel.org" , Mel Gorman , "linux-kernel@vger.kernel.org" , yanmin.zhang@intel.com, tim.c.chen@intel.com Subject: Re: [Bugme-new] [Bug 13690] New: nodes_clear cause hugepage unusable on non-NUMA machine References: <20090701183452.8660c8a9.akpm@linux-foundation.org> <4A4C17FD.3080404@kernel.org> <1246517111.15721.5.camel@alexs-hp> <4A4C74D8.30809@kernel.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1570 Lines: 38 Christoph Lameter wrote: > On Thu, 2 Jul 2009, Yinghai Lu wrote: > >> Index: linux-2.6/arch/x86/mm/init_64.c >> =================================================================== >> --- linux-2.6.orig/arch/x86/mm/init_64.c >> +++ linux-2.6/arch/x86/mm/init_64.c >> @@ -598,8 +598,14 @@ void __init paging_init(void) >> >> sparse_memory_present_with_active_regions(MAX_NUMNODES); >> sparse_init(); >> - /* clear the default setting with node 0 */ >> +#if MAX_NUMNODES > 1 >> + /* >> + * clear the default setting with node 0 >> + * note: don't clear it, node_set_state will do nothing >> + * (aka set it back) when numa support is not compiled in >> + */ >> nodes_clear(node_states[N_NORMAL_MEMORY]); > > The problem was that nodes_clear() does not fall back to a noop on !NUMA. > The node_set/clear_states() operations do become noops. > > Could we make it more consistent by using only operations of the same > type? F.e. Add a node_clearall_states() in include/linux/nodemask.h that > falls back to a noop on !NUMA like the node_*_states operation? > > Another options is to restore node_states[N_NORMAL_MEMORY] to its > initial condition. See the definition of node_states in page_alloc.c. could use node_clear_state(0, N_NORMAL_MEMORY) instead. because default one only have node 0 set in that mask. YH -- 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/