From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f169.google.com (mail-ig0-f169.google.com [209.85.213.169]) by kanga.kvack.org (Postfix) with ESMTP id 4DED56B0038 for ; Mon, 24 Nov 2014 17:55:22 -0500 (EST) Received: by mail-ig0-f169.google.com with SMTP id hl2so5858668igb.4 for ; Mon, 24 Nov 2014 14:55:22 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id h3si110119icq.78.2014.11.24.14.55.20 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 24 Nov 2014 14:55:21 -0800 (PST) Date: Mon, 24 Nov 2014 14:55:42 -0800 From: Andrew Morton 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> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: 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 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, 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/ . Don't email: email@kvack.org