Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935751Ab3DKCkh (ORCPT ); Wed, 10 Apr 2013 22:40:37 -0400 Received: from mail-qa0-f46.google.com ([209.85.216.46]:41867 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751496Ab3DKCkg (ORCPT ); Wed, 10 Apr 2013 22:40:36 -0400 Message-ID: <5166229D.2090904@gmail.com> Date: Thu, 11 Apr 2013 10:40:29 +0800 From: Simon Jeons User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: "H. Peter Anvin" CC: Frantisek Hrbata , linux-kernel@vger.kernel.org, linux-mm@kvack.org, tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, oleg@redhat.com, kamaleshb@in.ibm.com Subject: Re: [PATCH] x86: add phys addr validity check for /dev/mem mmap References: <1364905733-23937-1-git-send-email-fhrbata@redhat.com> <515B2802.1050405@zytor.com> <515CD359.40004@gmail.com> <515CD3BF.5010104@zytor.com> In-Reply-To: <515CD3BF.5010104@zytor.com> 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 Content-Length: 792 Lines: 22 Hi H.Peter, On 04/04/2013 09:13 AM, H. Peter Anvin wrote: > On 04/03/2013 06:11 PM, Simon Jeons wrote: >> Why we consider boot_cpu_data.x86_phys_bits instead of e820 map here? >> > Because x86_phys_bits is what controls how much address space the > processor has. e820 tells us how much *RAM* the machine has, or > specifically, how much RAM the machine had on boot. I have 8GB memory in my machine, but when I accumulated every e820 ranges which dump in dmesg, there are 25MB memory less then 8GB(1024*8) memory, why 25MB miss? > > -hpa > -- 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/