From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx131.postini.com [74.125.245.131]) by kanga.kvack.org (Postfix) with SMTP id 699976B004F for ; Thu, 8 Dec 2011 16:06:06 -0500 (EST) Received: by iahk25 with SMTP id k25so4103628iah.14 for ; Thu, 08 Dec 2011 13:06:05 -0800 (PST) Date: Thu, 8 Dec 2011 13:06:03 -0800 (PST) From: David Rientjes Subject: Re: [PATCH v3 3/3] slub: min order when debug_guardpage_minorder > 0 In-Reply-To: <20111208073316.GA2402@redhat.com> Message-ID: References: <1321633507-13614-1-git-send-email-sgruszka@redhat.com> <1321633507-13614-3-git-send-email-sgruszka@redhat.com> <20111208073316.GA2402@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Stanislaw Gruszka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman , Andrea Arcangeli , Andrew Morton , "Rafael J. Wysocki" , Christoph Lameter On Thu, 8 Dec 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 > SLUB will output a line in the dmesg that specifies the possible orders so it would be helpful to also note that those can change because of debug_guardpage_minorder in both Documentation/vm/slub.txt and the "order" file entry in Documentation/ABI/testing/sysfs-kernel-slab. Thanks! -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org