From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx165.postini.com [74.125.245.165]) by kanga.kvack.org (Postfix) with SMTP id 52AA76B0005 for ; Wed, 10 Apr 2013 22:58:53 -0400 (EDT) Received: by mail-da0-f53.google.com with SMTP id n34so482144dal.12 for ; Wed, 10 Apr 2013 19:58:52 -0700 (PDT) Message-ID: <516626E4.4000507@gmail.com> Date: Thu, 11 Apr 2013 10:58:44 +0800 From: Simon Jeons MIME-Version: 1.0 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> <5166229D.2090904@gmail.com> <51662492.1030100@zytor.com> In-Reply-To: <51662492.1030100@zytor.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: 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 Hi H.Peter, On 04/11/2013 10:48 AM, H. Peter Anvin wrote: > On 04/10/2013 07:40 PM, Simon Jeons wrote: >> 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? >> > For whatever reason your BIOS is stealing some memory, possibly for video. Thanks for your quick response. ;-) My machine is new which have i7 cpu. How much memory video need? 8MB? Why I miss 25MB? > > -hpa > > -- 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