From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754724Ab1LLXSp (ORCPT ); Mon, 12 Dec 2011 18:18:45 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:54540 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754503Ab1LLXSm (ORCPT ); Mon, 12 Dec 2011 18:18:42 -0500 From: "Rafael J. Wysocki" To: Stanislaw Gruszka Subject: Re: [PATCH -mm] slub: document setting min order with debug_guardpage_minorder > 0 Date: Tue, 13 Dec 2011 00:21:41 +0100 User-Agent: KMail/1.13.6 (Linux/3.2.0-rc5+; KDE/4.6.0; x86_64; ; ) Cc: David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman , Andrea Arcangeli , Andrew Morton , Christoph Lameter References: <1321633507-13614-1-git-send-email-sgruszka@redhat.com> <20111212145948.GA2380@redhat.com> In-Reply-To: <20111212145948.GA2380@redhat.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201112130021.41429.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, December 12, 2011, Stanislaw Gruszka wrote: > Signed-off-by: Stanislaw Gruszka > --- > English is hard (definitely harder than C language :-), so please correct > me, if I wrote something wrong. > > Documentation/ABI/testing/sysfs-kernel-slab | 4 +++- > Documentation/vm/slub.txt | 4 +++- > 2 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-kernel-slab b/Documentation/ABI/testing/sysfs-kernel-slab > index 8b093f8..d84ca80 100644 > --- a/Documentation/ABI/testing/sysfs-kernel-slab > +++ b/Documentation/ABI/testing/sysfs-kernel-slab > @@ -345,7 +345,9 @@ Description: > allocated. It is writable and can be changed to increase the > number of objects per slab. If a slab cannot be allocated > because of fragmentation, SLUB will retry with the minimum order > - possible depending on its characteristics. > + possible depending on its characteristics. Added trailing whitespace (please remove). > + When debug_guardpage_minorder > 0 parameter is specified, the > + minimum possible order is used and cannot be changed. Well, I'm not sure what you wanted to say, actually? How does one change debug_guardpage_minorder (or specify it), for example? Is it a kernel command-line switch? Also I'm not sure what "cannot be changed" is supposed to mean. Does it mean that /sys/cache/slab/cache/order has no effect in that case? > > What: /sys/kernel/slab/cache/order_fallback > Date: April 2008 > diff --git a/Documentation/vm/slub.txt b/Documentation/vm/slub.txt > index f464f47..dbf02ad 100644 > --- a/Documentation/vm/slub.txt > +++ b/Documentation/vm/slub.txt > @@ -131,7 +131,9 @@ slub_min_objects. > slub_max_order specified the order at which slub_min_objects should no > longer be checked. This is useful to avoid SLUB trying to generate > super large order pages to fit slub_min_objects of a slab cache with > -large object sizes into one high order page. > +large object sizes into one high order page. Setting parameter > +debug_guardpage_minorder > 0 forces setting slub_max_order to 0, what > +cause minimum possible order of slabs allocation. > > SLUB Debug output > ----------------- > Rafael