From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754058Ab0AHTsF (ORCPT ); Fri, 8 Jan 2010 14:48:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753520Ab0AHTsB (ORCPT ); Fri, 8 Jan 2010 14:48:01 -0500 Received: from mga12.intel.com ([143.182.124.36]:48939 "EHLO azsmga102.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752437Ab0AHTsB (ORCPT ); Fri, 8 Jan 2010 14:48:01 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.47,316,1257148800"; d="scan'208";a="230758496" Message-ID: <4B478BEA.1010504@linux.intel.com> Date: Fri, 08 Jan 2010 20:47:54 +0100 From: Andi Kleen User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: "H. Peter Anvin" CC: "Zheng, Shaohui" , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "y-goto@jp.fujitsu.com" , Dave Hansen , "Wu, Fengguang" , "x86@kernel.org" Subject: Re: [PATCH - resend] Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel(v1) References: <4B46BC6F.5060607@kernel.org> In-Reply-To: <4B46BC6F.5060607@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org H. Peter Anvin wrote: > On 01/07/2010 07:32 PM, Zheng, Shaohui wrote: >> Resend the patch to the mailing-list, the original patch URL is >> http://patchwork.kernel.org/patch/69075/, it is not accepted without comments, >> sent it again to review. >> >> Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel >> >> The new added memory can not be access by interface /dev/mem, because we do not >> update the variable high_memory. This patch add a new e820 entry in e820 table, >> and update max_pfn, max_low_pfn and high_memory. >> >> We add a function update_pfn in file arch/x86/mm/init.c to udpate these >> varibles. Memory hotplug does not make sense on 32-bit kernel, so we did not >> concern it in this function. >> > > Memory hotplug makes sense on 32-bit kernels, at least in virtual > environments. No VM currently supports it to my knowledge. They all use traditional balooning. If someone adds that they can still fix it, but right now fixing it on 64bit is the important part. -Andi 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 2B00B6B0044 for ; Fri, 8 Jan 2010 14:48:03 -0500 (EST) Message-ID: <4B478BEA.1010504@linux.intel.com> Date: Fri, 08 Jan 2010 20:47:54 +0100 From: Andi Kleen MIME-Version: 1.0 Subject: Re: [PATCH - resend] Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel(v1) References: <4B46BC6F.5060607@kernel.org> In-Reply-To: <4B46BC6F.5060607@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: "H. Peter Anvin" Cc: "Zheng, Shaohui" , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "y-goto@jp.fujitsu.com" , Dave Hansen , "Wu, Fengguang" , "x86@kernel.org" List-ID: H. Peter Anvin wrote: > On 01/07/2010 07:32 PM, Zheng, Shaohui wrote: >> Resend the patch to the mailing-list, the original patch URL is >> http://patchwork.kernel.org/patch/69075/, it is not accepted without comments, >> sent it again to review. >> >> Memory-Hotplug: Fix the bug on interface /dev/mem for 64-bit kernel >> >> The new added memory can not be access by interface /dev/mem, because we do not >> update the variable high_memory. This patch add a new e820 entry in e820 table, >> and update max_pfn, max_low_pfn and high_memory. >> >> We add a function update_pfn in file arch/x86/mm/init.c to udpate these >> varibles. Memory hotplug does not make sense on 32-bit kernel, so we did not >> concern it in this function. >> > > Memory hotplug makes sense on 32-bit kernels, at least in virtual > environments. No VM currently supports it to my knowledge. They all use traditional balooning. If someone adds that they can still fix it, but right now fixing it on 64bit is the important part. -Andi -- 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