From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751729Ab1LHHdQ (ORCPT ); Thu, 8 Dec 2011 02:33:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40182 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751591Ab1LHHdO (ORCPT ); Thu, 8 Dec 2011 02:33:14 -0500 Date: Thu, 8 Dec 2011 08:33:17 +0100 From: Stanislaw Gruszka To: David Rientjes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman , Andrea Arcangeli , Andrew Morton , "Rafael J. Wysocki" , Christoph Lameter Subject: Re: [PATCH v3 3/3] slub: min order when debug_guardpage_minorder > 0 Message-ID: <20111208073316.GA2402@redhat.com> References: <1321633507-13614-1-git-send-email-sgruszka@redhat.com> <1321633507-13614-3-git-send-email-sgruszka@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 07, 2011 at 02:07:55PM -0800, David Rientjes wrote: > On Fri, 18 Nov 2011, Stanislaw Gruszka wrote: > > > diff --git a/mm/slub.c b/mm/slub.c > > index 7d2a996..a66be56 100644 > > --- a/mm/slub.c > > +++ b/mm/slub.c > > @@ -3645,6 +3645,9 @@ void __init kmem_cache_init(void) > > struct kmem_cache *temp_kmem_cache_node; > > unsigned long kmalloc_size; > > > > + if (debug_guardpage_minorder()) > > + slub_max_order = 0; > > + > > kmem_size = offsetof(struct kmem_cache, node) + > > nr_node_ids * sizeof(struct kmem_cache_node *); > > > > I'd recommend at least printing a warning about why slub_max_order was > reduced because users may be concerned why they can't now change any > cache's order with /sys/kernel/slab/cache/order. It's only happen with debug_guardpage_minorder=N parameter, so perhaps I'll just document that in kernel-parameters.txt Thanks Stanislaw