From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH 3/4] KVM: MMU: reduce the size of mmu_page_path Date: Fri, 25 Mar 2016 21:48:53 +0800 Message-ID: <56F541C5.6090904@linux.intel.com> References: <1458911978-19430-1-git-send-email-guangrong.xiao@linux.intel.com> <1458911978-19430-3-git-send-email-guangrong.xiao@linux.intel.com> <56F54103.6020508@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org To: Paolo Bonzini Return-path: Received: from mga02.intel.com ([134.134.136.20]:35450 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751091AbcCYNtq (ORCPT ); Fri, 25 Mar 2016 09:49:46 -0400 In-Reply-To: <56F54103.6020508@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 03/25/2016 09:45 PM, Paolo Bonzini wrote: > > > 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... If you do not like this one, we can just make the .index is [PT64_ROOT_LEVEL - 1] and keep the sentinel in .parents[], that little change and nice code shape.