Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751174AbaKXWzW (ORCPT ); Mon, 24 Nov 2014 17:55:22 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56591 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750761AbaKXWzV (ORCPT ); Mon, 24 Nov 2014 17:55:21 -0500 Date: Mon, 24 Nov 2014 14:55:42 -0800 From: Andrew Morton To: Joonsoo Kim Cc: Mel Gorman , Johannes Weiner , Minchan Kim , Dave Hansen , Michal Nazarewicz , Jungsoo Son , Ingo Molnar , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/8] mm/debug-pagealloc: make debug-pagealloc boottime configurable Message-Id: <20141124145542.08b97076.akpm@linux-foundation.org> In-Reply-To: <1416816926-7756-4-git-send-email-iamjoonsoo.kim@lge.com> References: <1416816926-7756-1-git-send-email-iamjoonsoo.kim@lge.com> <1416816926-7756-4-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: Sylpheed 2.7.1 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 24 Nov 2014 17:15:21 +0900 Joonsoo Kim wrote: > Now, we have prepared to avoid using debug-pagealloc in boottime. So > introduce new kernel-parameter to disable debug-pagealloc in boottime, > and makes related functions to be disabled in this case. > > Only non-intuitive part is change of guard page functions. Because > guard page is effective only if debug-pagealloc is enabled, turning off > according to debug-pagealloc is reasonable thing to do. > > ... > > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -858,6 +858,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > causing system reset or hang due to sending > INIT from AP to BSP. > > + disable_debug_pagealloc > + [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this > + parameter allows user to disable it at boot time. > + With this parameter, we can avoid allocating huge > + chunk of memory for debug pagealloc and then > + the system will work mostly same with the kernel > + built without CONFIG_DEBUG_PAGEALLOC. > + Weren't we going to make this default to "off", require a boot option to turn debug_pagealloc on? -- 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/