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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1E7DC04A68 for ; Fri, 29 Jul 2022 17:07:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232803AbiG2RHH (ORCPT ); Fri, 29 Jul 2022 13:07:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229700AbiG2RHF (ORCPT ); Fri, 29 Jul 2022 13:07:05 -0400 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DB8054ACD for ; Fri, 29 Jul 2022 10:07:05 -0700 (PDT) Received: by mail-pf1-x429.google.com with SMTP id c3so5119497pfb.13 for ; Fri, 29 Jul 2022 10:07:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=9o/kpxtwtGSAJRz7togZqH/jX2IzYG9txOU/MkOdGsk=; b=d7rrhYFDw6/dZgg1zbGYEELi+Ig6rFIt8U9NslLM0uU54fjiN5LGx1yttndq6MRsU9 +7RsjMcHBPvo9jWret2P4sPOppbiMdG8cI1kd+akSPTG+EObbBmqLkCpNfuGcK8v3et/ 00EpnIyAJBLgzqog02E2FLDm/yJUXIJ24ox/5REaSArOoUXct80bc5LcGQIzVSKmN6DM Zv7n761ElhQDgSA1FTeDvln1HSKX32ZpEXSPVXF5BhIwAT4/VNDBqvWnrmu3oVxPtDXx 9fH7sPTJB4vfg1PdPzrZtt3Sh82x5Vf8NAASPWzFvLQmI4EvMB13nINjdJy2lWSs8Oo/ RhFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=9o/kpxtwtGSAJRz7togZqH/jX2IzYG9txOU/MkOdGsk=; b=DSC6DNWWMseEBZqOzRcFP1LBoI3hWNkFshLxWbqwlFKCrPyQxGboGkuxHMeS+YTdrR GYb7aicW1ARnA+KKuQeG/A47bM+Zn0ICRFhxmlEIjMMKX385M1N3RdIjN6s+p9vMkAky XSg0NQifSYOpwpyXOeFzipkrZtdG/T5HdVFvspeM6ob4cfUNNQLZcSC0zLzpIswmpZ96 OAzbOF2u8k0O8qm4OPk2enYHCEruBYS4tU5zqxAWNgNMk+0DItdX/wP1nIv5Rpol5Uws 4i5XRSR+CoPbrUrI9McnW7Eadri8oDTvUfTRv9+pGyZ4ZAWY15qK0htViZSenzBYv0Rb uPAA== X-Gm-Message-State: AJIora+Bpbbox3KcjKU9qlo3P2XQnoaZzJwn0zhgRF550iadNqu6gJDZ KAOIEJHkUWvxgXYUIWD2xqU= X-Google-Smtp-Source: AGRyM1upLon9wbIMfbCwqO3JYhACcZurI2iHO4roReNV/ZHzKqhAtd1uue50i8179qkbq7tKRlvklA== X-Received: by 2002:a63:1213:0:b0:41a:8d6b:3e80 with SMTP id h19-20020a631213000000b0041a8d6b3e80mr3571086pgl.388.1659114424345; Fri, 29 Jul 2022 10:07:04 -0700 (PDT) Received: from smtpclient.apple ([66.170.99.113]) by smtp.gmail.com with ESMTPSA id y62-20020a62ce41000000b00528d580cb45sm3145326pfg.127.2022.07.29.10.07.03 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 29 Jul 2022 10:07:03 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.1\)) Subject: Re: [PATCH RFC 0/4] mm: Remember young bit for migration entries From: Nadav Amit In-Reply-To: <20220729014041.21292-1-peterx@redhat.com> Date: Fri, 29 Jul 2022 10:07:02 -0700 Cc: Linux MM , LKML , Huang Ying , Andrea Arcangeli , Andrew Morton , "Kirill A . Shutemov" , Hugh Dickins , David Hildenbrand , Vlastimil Babka Content-Transfer-Encoding: quoted-printable Message-Id: <6C0B267E-E36D-4014-8308-B948247D7FED@gmail.com> References: <20220729014041.21292-1-peterx@redhat.com> To: Peter Xu X-Mailer: Apple Mail (2.3696.120.41.1.1) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Jul 28, 2022, at 6:40 PM, Peter Xu wrote: > [Marking as RFC; only x86 is supported for now, plan to add a few more > archs when there's a formal version] >=20 > Problem > =3D=3D=3D=3D=3D=3D=3D >=20 > When migrate a page, right now we always mark the migrated page as = old. > The reason could be that we don't really know whether the page is hot = or > cold, so we could have taken it a default negative assuming that's = safer. Looks good to me. I just wonder whether the order of the patches should be different. I = always understood that separating the =E2=80=9Cenabling=E2=80=9D patch from the = others is not a good practice, since it complicates bisection. I guess it is more of a = minor issue for such a small patch-set=E2=80=A6