From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1A50C65C31 for ; Sat, 6 Oct 2018 14:42:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B11042089D for ; Sat, 6 Oct 2018 14:42:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B11042089D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728080AbeJFVpc (ORCPT ); Sat, 6 Oct 2018 17:45:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39632 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727789AbeJFVpc (ORCPT ); Sat, 6 Oct 2018 17:45:32 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 636073086262; Sat, 6 Oct 2018 14:41:58 +0000 (UTC) Received: from localhost (ovpn-8-20.pek2.redhat.com [10.72.8.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4A5AA608F6; Sat, 6 Oct 2018 14:41:56 +0000 (UTC) Date: Sat, 6 Oct 2018 22:41:53 +0800 From: Baoquan He To: Ingo Molnar Cc: "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, x86@kernel.org, linux-doc@vger.kernel.org, tglx@linutronix.de, thgarnie@google.com, corbet@lwn.net, Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Linus Torvalds , Andrew Morton Subject: Re: [PATCH 4/3] x86/mm/doc: Enhance the x86-64 virtual memory layout descriptions Message-ID: <20181006144153.GE5140@MiWiFi-R3L-srv> References: <20181006084327.27467-1-bhe@redhat.com> <20181006122259.GB418@gmail.com> <20181006123322.GA60572@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181006123322.GA60572@gmail.com> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Sat, 06 Oct 2018 14:41:58 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/06/18 at 02:33pm, Ingo Molnar wrote: > > * Ingo Molnar wrote: > > > +======================================================== > > +| Complete virtual memory map with 4-level page tables | > > +======================================================== > > > +-------------------------------------------------------------------------------- > > +start addr | offset | end addr | size | VM area description > > +-----------------|------------|------------------|---------|-------------------- > > > + > > +# Identical layout to the 56-bit one from here on: > > + > > +ffffff8000000000 | -512 GB | fffffffeefffffff | ~507 GB | ... unused hole > > +ffffffef00000000 | -68 GB | fffffffeffffffff | 64 GB | EFI region mapping space > > > +======================================================== > > +| Complete virtual memory map with 5-level page tables | > > +======================================================== > > > +ffffff8000000000 | -0.5 TB | ffffffeeffffffff | 444 GB | ... unused hole > > + > > +# Identical layout to the 47-bit one from here on: > > + > > +ffffffef00000000 | -68 GB | fffffffeffffffff | 64 GB | EFI region mapping space > > So patch #2 appears to have introduced an error/typo in the 47-bit table. Note the weird size > and discontinuity of the 'unused hole' in the 47-bit table, and compare it with 56-bit table: > > fffffffeefffffff > ffffffeeffffffff > > (Note how the incorrect end address was cargo-cult-copied into the 'size' field of ~507 GB...) > > The correct number is the 56-bit one, and both tables should show the following identical > layout: > > ffffff8000000000 | -512 GB | fffffffeefffffff | 444 GB | ... unused hole > ffffffef00000000 | -68 GB | fffffffeffffffff | 64 GB | EFI region mapping space > > Agreed? Yes, you are right. I wondered why the size is a weird unaligned value. Sorry about that. Thanks Baoquan