From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751612AbdFGKrU (ORCPT ); Wed, 7 Jun 2017 06:47:20 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:35391 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751522AbdFGKrS (ORCPT ); Wed, 7 Jun 2017 06:47:18 -0400 Date: Wed, 7 Jun 2017 13:47:15 +0300 From: "Kirill A. Shutemov" To: =?iso-8859-1?B?Suly9G1l?= Glisse Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andy Lutomirski , Ingo Molnar , "Kirill A . Shutemov" , Logan Gunthorpe Subject: Re: [PATCH] x86/mm/hotplug: fix BUG_ON() after hotremove Message-ID: <20170607104715.5niuwk42fhahbftk@node.shutemov.name> References: <20170606173512.7378-1-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170606173512.7378-1-jglisse@redhat.com> User-Agent: NeoMutt/20170428 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 06, 2017 at 01:35:12PM -0400, Jérôme Glisse wrote: > With commit af2cf278ef4f we no longer free pud so that we > do not have synchronize all pgd on hotremove/vfree. But the > new 5 level page table code re-added that code f2a6a705 and > thus we now trigger a BUG_ON() l128 in sync_global_pgds() > > This patch remove free_pud() like in af2cf278ef4f Good catch. Thanks! But I think we only need to skip free_pud_table() for 4-level paging. If we don't we would leave 513 page tables around instead of one in 5-level paging case. I don't think it's acceptable. And please use patch subject lines along with commit hashes to simplify reading commit message. -- Kirill A. Shutemov