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=-4.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 A59CFC433E2 for ; Tue, 14 Jul 2020 10:19:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A64522200 for ; Tue, 14 Jul 2020 10:19:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="IY4UxVnz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726820AbgGNKTv (ORCPT ); Tue, 14 Jul 2020 06:19:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726398AbgGNKTu (ORCPT ); Tue, 14 Jul 2020 06:19:50 -0400 Received: from mail-lf1-x141.google.com (mail-lf1-x141.google.com [IPv6:2a00:1450:4864:20::141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 047FDC061794 for ; Tue, 14 Jul 2020 03:19:49 -0700 (PDT) Received: by mail-lf1-x141.google.com with SMTP id g139so11028009lfd.10 for ; Tue, 14 Jul 2020 03:19:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=2mWXGb8qDwWepwC9GtvAtfuTcRSkTZNoUz/7tBuj5w4=; b=IY4UxVnzzRcsGwYrBKqt/5e25O/9f0c09XQ9ySHCczZy/i0f0gYx9QLwZtXoJ8X7ZM 5MW8/0dDgLBTX6Q4TE87LTvdoHKvCj57HHbHI0HpjGL8h/cg6/kw5hx+04UxsaoDCNy+ P4tPvwDURrTeOKfPv921zK42DMIAvxiJ7IIlqlJ3rkxhhK91YOcLC6HOEQ1aN6fJ03+Q Is/Mh1WHNi2qXNUoD8ejk83nG8RWH6H/eDqQWhGgwWMPujV0VJuPgtd0GpFSw0cBeR0q 2EsxV4r06bH603rAdR8GS4qX8bMh9OWqM77a1EXmIccI7Tgba33H2zXPPfZ+bPQrU9Wl /k1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=2mWXGb8qDwWepwC9GtvAtfuTcRSkTZNoUz/7tBuj5w4=; b=gwnKfIN2d/GGCAUEZOvuL0n2YayNSa+uj4f6zmQgSZvovUNiQA0e9ioZh1rnjL5Ong wWnsyxjXU2sEwAr1j7XYZaZIOhLcKCqJGlqWsUVPUmsHmf4navHzh/+xtwcCxI6GEiaR DJGGPQPNhmu2a3UvoX5mvqhmOKRt4g+q9rQ2Ef61sJmS2moK7MzDbEnwhdgNv/GZ0/B3 oAi0MObsKHiQZE8xa+3cMPQOrhCHHoLiufoOD7pG0P4AX1KZQFeTym1fu1mCWozMzcoN Y3h6pjSVfdjLgq4jyBmM0hNRvsWKaBlhwbEeF4cu9f3cKGWgEVVtXJys05C/UAsKD6ld +4xw== X-Gm-Message-State: AOAM532x/CqvlfHOhw51QV2LaPlJjEJrFIpKksFBGEH8ImRTYbwlXIPA onW6u2IOnQzKoFSxWP2CyTmHrQ== X-Google-Smtp-Source: ABdhPJw/OsMOz/4ZB1ZoSYenOQRRXbfc7EqRKqARM2W6By60PrLuXAdBdxPvMyyECZzfP/PMH7riHg== X-Received: by 2002:ac2:5a4b:: with SMTP id r11mr1882755lfn.39.1594721988316; Tue, 14 Jul 2020 03:19:48 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id 11sm4540766lju.102.2020.07.14.03.19.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Jul 2020 03:19:47 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 2C21D1020F7; Tue, 14 Jul 2020 13:19:51 +0300 (+03) Date: Tue, 14 Jul 2020 13:19:51 +0300 From: "Kirill A. Shutemov" To: Vlastimil Babka Cc: Robbie Ko , linux-mm@kvack.org, LKML , linux-btrfs@vger.kernel.org, Roman Gushchin , David Sterba , "Kirill A. Shutemov" Subject: Re: [PATCH] mm : fix pte _PAGE_DIRTY bit when fallback migrate page Message-ID: <20200714101951.6osakxdgbhrnfrbd@box> References: <20200709024808.18466-1-robbieko@synology.com> <859c810e-376e-5e8b-e8a5-0da3f83315d1@suse.cz> <80b55fcf-def1-8a83-8f53-a22f2be56244@synology.com> <433e26b0-5201-129a-4afe-4881e42781fa@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <433e26b0-5201-129a-4afe-4881e42781fa@suse.cz> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Tue, Jul 14, 2020 at 11:46:12AM +0200, Vlastimil Babka wrote: > On 7/13/20 3:57 AM, Robbie Ko wrote: > > > > Vlastimil Babka 於 2020/7/10 下午11:31 寫道: > >> On 7/9/20 4:48 AM, robbieko wrote: > >>> From: Robbie Ko > >>> > >>> When a migrate page occurs, we first create a migration entry > >>> to replace the original pte, and then go to fallback_migrate_page > >>> to execute a writeout if the migratepage is not supported. > >>> > >>> In the writeout, we will clear the dirty bit of the page and use > >>> page_mkclean to clear the dirty bit along with the corresponding pte, > >>> but page_mkclean does not support migration entry. I don't follow the scenario. When we establish migration entries with try_to_unmap(), it transfers dirty bit from PTE to the page. -- Kirill A. Shutemov