From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f44.google.com (mail-wm0-f44.google.com [74.125.82.44]) by kanga.kvack.org (Postfix) with ESMTP id 6C8A76B0005 for ; Wed, 27 Jan 2016 08:03:39 -0500 (EST) Received: by mail-wm0-f44.google.com with SMTP id n5so25402703wmn.0 for ; Wed, 27 Jan 2016 05:03:39 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id i11si12108592wmf.7.2016.01.27.05.03.38 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 27 Jan 2016 05:03:38 -0800 (PST) Subject: Re: [PATCH/RFC 3/3] s390: query dynamic DEBUG_PAGEALLOC setting References: <1453799905-10941-1-git-send-email-borntraeger@de.ibm.com> <1453799905-10941-4-git-send-email-borntraeger@de.ibm.com> <20160126181903.GB4671@osiris> <20160127001918.GA7089@js1304-P5Q-DELUXE> <20160127005920.GB7089@js1304-P5Q-DELUXE> <56A8BB15.9070305@suse.cz> <56A8BC6D.9080101@de.ibm.com> From: Vlastimil Babka Message-ID: <56A8C028.7050305@suse.cz> Date: Wed, 27 Jan 2016 14:03:36 +0100 MIME-Version: 1.0 In-Reply-To: <56A8BC6D.9080101@de.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christian Borntraeger , Joonsoo Kim , David Rientjes Cc: Heiko Carstens , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, x86@kernel.org On 01/27/2016 01:47 PM, Christian Borntraeger wrote: > On 01/27/2016 01:41 PM, Vlastimil Babka wrote: >> On 01/27/2016 01:59 AM, Joonsoo Kim wrote: >> >> I think it might be worth also to convert debug_pagealloc_enabled() to be based >> on static key, like I did for page_owner [1]. That should help make it possible >> to have virtually no overhead when compiling kernel with CONFIG_DEBUG_PAGEALLOC >> without enabling it boot-time. I assume it's one of the goals here? > > We could do something like that but dump_stack and setup of the initial identity > mapping of the kernel as well as the initial page protection are not hot path > as far as I can tell. Any other places? Well, mostly kernel_map_pages() which is used in page allocation hotpaths. >> >> [1] http://www.spinics.net/lists/linux-mm/msg100795.html > > > > -- > 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 > -- 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