Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752580AbcCYNpq (ORCPT ); Fri, 25 Mar 2016 09:45:46 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35172 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750870AbcCYNpo (ORCPT ); Fri, 25 Mar 2016 09:45:44 -0400 Subject: Re: [PATCH 3/4] KVM: MMU: reduce the size of mmu_page_path To: Xiao Guangrong References: <1458911978-19430-1-git-send-email-guangrong.xiao@linux.intel.com> <1458911978-19430-3-git-send-email-guangrong.xiao@linux.intel.com> Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org From: Paolo Bonzini Message-ID: <56F54103.6020508@redhat.com> Date: Fri, 25 Mar 2016 14:45:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1458911978-19430-3-git-send-email-guangrong.xiao@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 655 Lines: 18 On 25/03/2016 14:19, Xiao Guangrong wrote: > Currently only PT64_ROOT_LEVEL - 1 levels are used, one additional entry > in .parent[] is used as a sentinel, the additional entry in .idx[] is > purely wasted > > This patch reduces its size and sets the sentinel on the upper level of > the place where we start from This patch and the previous one are basically redoing commit 0a47cd85833e ("KVM: MMU: Fix ubsan warnings", 2016-03-04). While you find your version easier to understand, I of course find mine easier. Rather than getting stuck in a ko fight, the solution is to stick with the code in KVM and add comments. I'll give it a try... Paolo