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 E7C37C19F2A for ; Thu, 4 Aug 2022 17:17:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235120AbiHDRRB (ORCPT ); Thu, 4 Aug 2022 13:17:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233238AbiHDRQ4 (ORCPT ); Thu, 4 Aug 2022 13:16:56 -0400 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C780F5C9D2 for ; Thu, 4 Aug 2022 10:16:54 -0700 (PDT) Received: by mail-pl1-x62c.google.com with SMTP id x23so427164pll.7 for ; Thu, 04 Aug 2022 10:16:54 -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=QHDKoLkk6GDmpCFPVivtCs2hgFz4v8Al+bShpzHhVfw=; b=VqJbMd6Unb+dMzpQ1YaxAmRZ3fFgtuIAqWSj3+TjBB4e0oQiM/3oxOl8xTK19I62E7 JumT6OWo9Ht5UVP7BN7bPyC+1pTS4ylOpwKKJ6emRCWMrtR8mOuoCThcaucl6qXTb3bm wcjqg/igMmjOQa8+VkEPOnssCigJzylCu0SKGRCqV9HUECfTu7uPDCTvAIufFaxAVD51 qZDeRRK17bN+lMTkt4LLmW3tHQOTnjODwjkT/aGU2Y/VFsWlunNeayGzyOjDe9tE6Kpv ar5PmjCYZndk/cHfxHYhkUW58IUzfbUdnylw4DfVkRCtoclRdUBV99J9491vPZCLxxwQ +tBw== 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=QHDKoLkk6GDmpCFPVivtCs2hgFz4v8Al+bShpzHhVfw=; b=zuFeXHQb5gKA7RdUG6LXPxrl10hN2b/ARW9aidcEINXWvjST28gkD3oaPx6PIDPddk alt8BOLX6YyXW5JkmWdCThlwgMsrmtUWIvYGfQO5rM7F1nlRuICQT1jjRtjhzW98mjLb V4GkTw468P9Qu4Gi7aevEwYaRCKNo7OZhnBCBtnNZsvxdekXtZahyUZwIv9Z12VtAziQ E6MzW5Tgde456Lmlv+1HLhNa+PSaG3ZyYhYk950fiFFgJCFSLnbglLrBMUF2a31F6dT7 p8TUY7WVpWsw4fx3k2bn/2dt0L0FdCo76Ctbuj0j5KJXgVaJmsMcOYVpvVazRNyxGaC3 d7EA== X-Gm-Message-State: ACgBeo3yVUvxctJY2kTyOTAf68c8EsFGVuBV7JFYZSuVHfq5/a8/2RI5 kRi2pY2iKhP3z1RbEz0sToY= X-Google-Smtp-Source: AA6agR7u9s3VhH6I4fg6XbCQBSObT3COgDyRm9I5NQPZb+wLdfqVv9G0l0QVaB45S9rdZISkc8gLwQ== X-Received: by 2002:a17:90a:fe92:b0:1f5:1b0b:1cd7 with SMTP id co18-20020a17090afe9200b001f51b0b1cd7mr3092551pjb.197.1659633414088; Thu, 04 Aug 2022 10:16:54 -0700 (PDT) Received: from smtpclient.apple (c-24-6-216-183.hsd1.ca.comcast.net. [24.6.216.183]) by smtp.gmail.com with ESMTPSA id t17-20020a170902e1d100b0016d8b0dfd61sm1179202pla.178.2022.08.04.10.16.52 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Aug 2022 10:16:53 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.1\)) Subject: Re: [PATCH 2/2] mm: Remember young bit for page migrations From: Nadav Amit In-Reply-To: Date: Thu, 4 Aug 2022 10:16:50 -0700 Cc: LKML , Linux MM , Andrea Arcangeli , Andi Kleen , Andrew Morton , Hugh Dickins , Huang Ying , "Kirill A . Shutemov" , Vlastimil Babka , David Hildenbrand , Minchan Kim Content-Transfer-Encoding: 7bit Message-Id: <40FDA6B1-EB53-484D-91A0-323606199C4E@gmail.com> References: <20220803012159.36551-1-peterx@redhat.com> <20220803012159.36551-3-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 Aug 4, 2022, at 10:07 AM, Peter Xu wrote: > On Wed, Aug 03, 2022 at 11:42:39PM -0700, Nadav Amit wrote: >> On Aug 3, 2022, at 9:45 AM, Peter Xu wrote: > > For this series, I can think more of dropping the young bit for migration > entry during these madvises (which should be relatively safe with the > pgtable held, since I don't need to touch the page but just modify the swap > entry within), but probably that's not really the major problem here, so > not sure whether that matters a huge lot (e.g., for FREE we should really > drop the whole entry?). Sounds good to me. I just had a look whether the swap entry should be checked and hit these additional cases, so I thought they are worthy of consideration. But as they are already not handling some cases, which is valid for madvise's hints, leaving it to later sounds fine. Handling migration entries anyhow might not be worthy of the risk of breaking something.