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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 E636AC04EB9 for ; Wed, 5 Dec 2018 16:29:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2DDD20879 for ; Wed, 5 Dec 2018 16:29:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A2DDD20879 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728233AbeLEQ3C (ORCPT ); Wed, 5 Dec 2018 11:29:02 -0500 Received: from mx2.suse.de ([195.135.220.15]:43476 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727195AbeLEQ3C (ORCPT ); Wed, 5 Dec 2018 11:29:02 -0500 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 74002AD94; Wed, 5 Dec 2018 16:28:59 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 841301E0DBB; Wed, 5 Dec 2018 17:28:57 +0100 (CET) Date: Wed, 5 Dec 2018 17:28:57 +0100 From: Jan Kara To: Jerome Glisse Cc: Jan Kara , linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Matthew Wilcox , Ross Zwisler , Dan Williams , Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= , Michal Hocko , Christian Koenig , Felix Kuehling , Ralph Campbell , John Hubbard , kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 2/3] mm/mmu_notifier: use structure for invalidate_range_start/end calls Message-ID: <20181205162857.GF30615@quack2.suse.cz> References: <20181203201817.10759-1-jglisse@redhat.com> <20181203201817.10759-3-jglisse@redhat.com> <20181205110416.GE22304@quack2.suse.cz> <20181205155357.GA3536@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20181205155357.GA3536@redhat.com> 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 On Wed 05-12-18 10:53:57, Jerome Glisse wrote: > On Wed, Dec 05, 2018 at 12:04:16PM +0100, Jan Kara wrote: > > Hi Jerome! > > > > On Mon 03-12-18 15:18:16, jglisse@redhat.com wrote: > > > From: Jérôme Glisse > > > > > > To avoid having to change many call sites everytime we want to add a > > > parameter use a structure to group all parameters for the mmu_notifier > > > invalidate_range_start/end cakks. No functional changes with this > > > patch. > > > > Two suggestions for the patch below: > > > > > @@ -772,7 +775,8 @@ static void dax_entry_mkclean(struct address_space *mapping, pgoff_t index, > > > * call mmu_notifier_invalidate_range_start() on our behalf > > > * before taking any lock. > > > */ > > > - if (follow_pte_pmd(vma->vm_mm, address, &start, &end, &ptep, &pmdp, &ptl)) > > > + if (follow_pte_pmd(vma->vm_mm, address, &range, > > > + &ptep, &pmdp, &ptl)) > > > continue; > > > > The change of follow_pte_pmd() arguments looks unexpected. Why should that > > care about mmu notifier range? I see it may be convenient but it doesn't look > > like a good API to me. > > Saddly i do not see a way around that one this is because of fs/dax.c > which does the mmu_notifier_invalidate_range_end while follow_pte_pmd > do the mmu_notifier_invalidate_range_start I see so this is really a preexisting problem with follow_pte_pmd() having ugly interface. After some thoughts I think your patch actually slightly improves the situation so OK. Honza -- Jan Kara SUSE Labs, CR