From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 1B5E66B0279 for ; Wed, 7 Jun 2017 06:47:19 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id a3so901992wma.12 for ; Wed, 07 Jun 2017 03:47:19 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id z52sor237053edb.19.2017.06.07.03.47.17 for (Google Transport Security); Wed, 07 Jun 2017 03:47:17 -0700 (PDT) Date: Wed, 7 Jun 2017 13:47:15 +0300 From: "Kirill A. Shutemov" 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> Sender: owner-linux-mm@kvack.org List-ID: 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 On Tue, Jun 06, 2017 at 01:35:12PM -0400, Jerome 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 -- 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