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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 8E756C76195 for ; Thu, 18 Jul 2019 08:46:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7023821849 for ; Thu, 18 Jul 2019 08:46:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389258AbfGRIq5 (ORCPT ); Thu, 18 Jul 2019 04:46:57 -0400 Received: from mx2.suse.de ([195.135.220.15]:47620 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726000AbfGRIq5 (ORCPT ); Thu, 18 Jul 2019 04:46:57 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 87F6FAD7B; Thu, 18 Jul 2019 08:46:56 +0000 (UTC) Date: Thu, 18 Jul 2019 10:46:54 +0200 From: Joerg Roedel To: Thomas Gleixner Cc: Joerg Roedel , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Ingo Molnar , Borislav Petkov , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 2/3] x86/mm: Sync also unmappings in vmalloc_sync_one() Message-ID: <20190718084654.GF13091@suse.de> References: <20190717071439.14261-1-joro@8bytes.org> <20190717071439.14261-3-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, On Wed, Jul 17, 2019 at 11:43:43PM +0200, Thomas Gleixner wrote: > On Wed, 17 Jul 2019, Joerg Roedel wrote: > > + > > + if (!pmd_present(*pmd_k)) > > + return NULL; > > else > > BUG_ON(pmd_pfn(*pmd) != pmd_pfn(*pmd_k)); > > So in case of unmap, this updates only the first entry in the pgd_list > because vmalloc_sync_all() will break out of the iteration over pgd_list > when NULL is returned from vmalloc_sync_one(). > > I'm surely missing something, but how is that supposed to sync _all_ page > tables on unmap as the changelog claims? No, you are right, I missed that. It is a bug in this patch, the code that breaks out of the loop in vmalloc_sync_all() needs to be removed as well. Will do that in the next version. Thanks, Joerg