Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756755Ab0ANN6K (ORCPT ); Thu, 14 Jan 2010 08:58:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756740Ab0ANN6J (ORCPT ); Thu, 14 Jan 2010 08:58:09 -0500 Received: from mga11.intel.com ([192.55.52.93]:17541 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755445Ab0ANN6I (ORCPT ); Thu, 14 Jan 2010 08:58:08 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,275,1262592000"; d="scan'208";a="531260123" Date: Thu, 14 Jan 2010 21:24:51 +0800 From: Wu Fengguang To: KAMEZAWA Hiroyuki Cc: "Zheng, Shaohui" , "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" Subject: Re: [ RESEND PATCH v3] Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel Message-ID: <20100114132451.GA2546@localhost> References: <20100112170433.394be31b.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100112170433.394be31b.kamezawa.hiroyu@jp.fujitsu.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1215 Lines: 35 Kame, On Tue, Jan 12, 2010 at 05:04:33PM +0900, KAMEZAWA Hiroyuki wrote: > 3 points... > 1. I think this patch cannot be compiled in archs other than x86. Right ? > IOW, please add static inline dummy... Good catch! > 2. pgdat->[start,end], totalram_pages etc...are updated at memory hotplug. > Please place the hook nearby them. arch/x86/mm/init_64.c:arch_add_memory() updates max_pfn_mapped, in this sense it's equally OK to update max_pfn/max_low_pfn etc before the call to arch_add_memory() ;) > 3. I recommend you yo use memory hotplug notifier. > If it's allowed, it will be cleaner. Hmm, notifier is for _outsider_ subsystems. It smells a bit overkill to do notifier _inside_ the hotplug code. > It seems there are no strict ordering to update parameters this patch touches. I tend to agree. That said, it does help keep our mind straight if we do it in some logical order: max_pfn => max_pfn_mapped => totalram_pages etc. Thanks, Fengguang -- 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/