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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 88A18C76188 for ; Mon, 22 Jul 2019 11:08:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 526E620821 for ; Mon, 22 Jul 2019 11:08:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="E54nSq8Q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729874AbfGVLI2 (ORCPT ); Mon, 22 Jul 2019 07:08:28 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:35950 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727123AbfGVLI1 (ORCPT ); Mon, 22 Jul 2019 07:08:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=yI6oJAOD8RitgYpGXV7mavr3OofMjIjiw6wkaelvwj4=; b=E54nSq8QjpaTk0rNt3VrHCO3G 6kAbY17R0sFpqIBTjoU+pieKC/cHS4iMnbKh8gX3+6PGXNEtD32bKcxKbDVjDeGtIRJLxUcsyn1NN 3GyiIL+bgEf3zPDOl5k5dcOBYibUyF1CspeuBVydmylD8cU8ReuFqydxCS9WcVgKrGAONFHqfRk3P 3xKD3XQpielWtJY3iWAQHp8SPP086TCjGdfvdG64iqF/3g5gTd2JtJEO4Xq1DIXdHMHv9HoFO1LyB u/WSNkyznbiMOroeS+PsuvJ/+iYGhHxXZC4RdMUKrwj6QdG4S8hrisMyAv6rOmyJ2kVjY7TQY+G1M MkPPuOq3Q==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hpWB7-0002Eh-PH; Mon, 22 Jul 2019 11:08:25 +0000 Date: Mon, 22 Jul 2019 04:08:25 -0700 From: Matthew Wilcox To: Ira Weiny Cc: Ralph Campbell , linux-mm@kvack.org, linux-kernel@vger.kernel.org, John Hubbard , Vlastimil Babka , Christoph Lameter , Dave Hansen , =?iso-8859-1?B?Suly9G1l?= Glisse , "Kirill A . Shutemov" , Lai Jiangshan , Martin Schwidefsky , Pekka Enberg , Randy Dunlap , Andrey Ryabinin , Christoph Hellwig , Jason Gunthorpe , Andrew Morton , Linus Torvalds Subject: Re: [PATCH v2 1/3] mm: document zone device struct page field usage Message-ID: <20190722110825.GD363@bombadil.infradead.org> References: <20190719192955.30462-1-rcampbell@nvidia.com> <20190719192955.30462-2-rcampbell@nvidia.com> <20190721160204.GB363@bombadil.infradead.org> <20190722051345.GB6157@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190722051345.GB6157@iweiny-DESK2.sc.intel.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 21, 2019 at 10:13:45PM -0700, Ira Weiny wrote: > On Sun, Jul 21, 2019 at 09:02:04AM -0700, Matthew Wilcox wrote: > > On Fri, Jul 19, 2019 at 12:29:53PM -0700, Ralph Campbell wrote: > > > Struct page for ZONE_DEVICE private pages uses the page->mapping and > > > and page->index fields while the source anonymous pages are migrated to > > > device private memory. This is so rmap_walk() can find the page when > > > migrating the ZONE_DEVICE private page back to system memory. > > > ZONE_DEVICE pmem backed fsdax pages also use the page->mapping and > > > page->index fields when files are mapped into a process address space. > > > > > > Restructure struct page and add comments to make this more clear. > > > > NAK. I just got rid of this kind of foolishness from struct page, > > and you're making it harder to understand, not easier. The comments > > could be improved, but don't lay it out like this again. > > Was V1 of Ralphs patch ok? It seemed ok to me. Yes, v1 was fine. This seems like a regression.