From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 2D8C76B0071 for ; Tue, 12 Jan 2010 08:19:15 -0500 (EST) From: "Zheng, Shaohui" Date: Tue, 12 Jan 2010 21:17:40 +0800 Subject: RE: [ RESEND PATCH v3] Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel Message-ID: References: <20100112170433.394be31b.kamezawa.hiroyu@jp.fujitsu.com> <20100112175724.adfa04d6.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100112175724.adfa04d6.kamezawa.hiroyu@jp.fujitsu.com> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "ak@linux.intel.com" , "y-goto@jp.fujitsu.com" , Dave Hansen , "x86@kernel.org" List-ID: >=20 > 3 points... > 1. I think this patch cannot be compiled in archs other than x86. Right ? > IOW, please add static inline dummy... > [Zheng, Shaohui] Agree, I will add a static dummy function >=20 > 2. pgdat->[start,end], totalram_pages etc...are updated at memory hotplug= . > Please place the hook nearby them. > [Zheng, Shaohui] Agree. >=20 > 3. I recommend you yo use memory hotplug notifier. > If it's allowed, it will be cleaner. > It seems there are no strict ordering to update parameters this patch = touches. >=20 > [Zheng, Shaohui] Kame, do you means put the hook into function slab_mem_g= oing_online_callback, it seems a good idea. If we select this method, we wi= ll need not to update these variable in function add_memory explicitly. >=20 yes. I think callback is the best. [Zheng, Shaohui] Kame, I check the code carefully and write a simple patch,= I found the callback will never be executed. The only entrance of this cal= lback is in function online_pages/offline_pages, but I did not found explic= it call to these 2 functions. Do we need to add a memory_notify to trigger = this callback in function add_memory?=20 Thanks, -Kame Thanks & Regards, Shaohui -- 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