From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756726Ab2AKIEi (ORCPT ); Wed, 11 Jan 2012 03:04:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:5413 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754906Ab2AKIEg (ORCPT ); Wed, 11 Jan 2012 03:04:36 -0500 Date: Wed, 11 Jan 2012 09:03:32 +0100 From: Stanislaw Gruszka To: akpm@linux-foundation.org Cc: "Rafael J. Wysocki" , David Rientjes , linux-kernel@vger.kernel.org, Pekka Enberg Subject: [PATCH -mm v2] slub: document setting min order with debug_guardpage_minorder > 0 Message-ID: <20120111080320.GA2452@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 v1 -> v2: - remove trailing whitespace - note debug_guardpage_minorder is a command line parameter - make clear that writing to /sys/cache/slab/cache/order will have no effect with debug_guardpage_minorder > 0 Acked-by: David Rientjes Cc: Pekka Enberg Cc: "Rafael J. Wysocki" Signed-off-by: Stanislaw Gruszka --- Documentation/ABI/testing/sysfs-kernel-slab | 4 ++++ Documentation/vm/slub.txt | 5 ++++- 2 files changed, 8 insertions(+), 1 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-kernel-slab b/Documentation/ABI/testing/sysfs-kernel-slab index 8b093f8..91bd6ca 100644 --- a/Documentation/ABI/testing/sysfs-kernel-slab +++ b/Documentation/ABI/testing/sysfs-kernel-slab @@ -346,6 +346,10 @@ Description: 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. + When debug_guardpage_minorder=N (N > 0) parameter is specified + (see Documentation/kernel-parameters.txt), the minimum possible + order is used and this sysfs entry can not be used to change + the order at run time. What: /sys/kernel/slab/cache/order_fallback Date: April 2008 diff --git a/Documentation/vm/slub.txt b/Documentation/vm/slub.txt index f464f47..1514d9f 100644 --- a/Documentation/vm/slub.txt +++ b/Documentation/vm/slub.txt @@ -131,7 +131,10 @@ 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 command line +parameter debug_guardpage_minorder=N (N > 0), forces setting +slub_max_order to 0, what cause minimum possible order of slabs +allocation. SLUB Debug output ----------------- -- 1.7.1