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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 147E9C433DF for ; Fri, 10 Jul 2020 10:33:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E17BA2076A for ; Fri, 10 Jul 2020 10:33:22 +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="mII+P3go" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727865AbgGJKdV (ORCPT ); Fri, 10 Jul 2020 06:33:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726369AbgGJKdT (ORCPT ); Fri, 10 Jul 2020 06:33:19 -0400 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 814A4C08C5CE for ; Fri, 10 Jul 2020 03:33:19 -0700 (PDT) Received: by mail-lj1-x234.google.com with SMTP id q7so5903770ljm.1 for ; Fri, 10 Jul 2020 03:33:19 -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=7wcSEVgyD5Y3dugrOjCqv9VAWTaRIiDXcxelGf3UV2M=; b=mII+P3goT2djho8sZLapqR2ZO0BzJs7VFIU+jKjyv8cANY5LcCi7pvATB+/EZ2IDEp BAGAbApnVctDKvjDeXMHHf0J20Cv0BvvBVsaQPMQZ2fDEqfW2N8waquGalnNPdiH61el 5J6CLC9m0fRyfkLIEGDf3fICqmx6muoWdrLLee7Cm3LOVtlMSfCgA9lq7qlHW1Gr4dre wlJQb8eFXXT8Y0CU0X8BGIO8Pu1ooM5zs5+cxzlVe1WeF21XDi3s+Xh+LFWJ7PGBCYa9 kbMVXtbkphRNg7DNQtJ0Xw90E36pD5J3JQBLPRR5m5ZVtgPlXK+IXrDTZUzjKqtZP4Sh I/QA== 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=7wcSEVgyD5Y3dugrOjCqv9VAWTaRIiDXcxelGf3UV2M=; b=b/9eTlqbI2uv1ZYaDHrPTnH/dRHsLG9BTpdTUZnikrQImLnktOwBkkaEhR1ZkUYnl2 0AAfhV79yNpDpwu5BNl0Ck6XAVJjXaAZsMJ6qrBAvT5/jJ3n437G8LoweZuCd3K3p1IT LGCv+qDT/4I3ggcvJ4zrOE9o8/9khNKdVOfHmbErr7r4NKd7W9nmRH+HyugcNmw+EgvJ jz8v67r/Sg7J2XJ0v1yFhGFxTLbHHJjHlZq4MSwMNodPGDOGc3hoMp6tiRFii6D3aqRg 3LliDV3ZlGwdTxebvRq+11pfaZo3Qi6UqTl8uedXw4/eZUXr/QtKQXGUu8huvIUhS091 Gz1A== X-Gm-Message-State: AOAM531R89wr55wpJEjrit5gTT07Gx8W4ST/LRsZF+ZJrGmL41zGjm5a qHDwD3rP5BUp3Ksd6/efOEtVLIzRwdI= X-Google-Smtp-Source: ABdhPJzIvkfX42cr5qxUwq/2hylNYWi1DXtCGvHf/btnFUlSfBwrWlICTxh9aCET97yOK8KhpJuTvA== X-Received: by 2002:a2e:b4d3:: with SMTP id r19mr24308257ljm.150.1594377196920; Fri, 10 Jul 2020 03:33:16 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id w2sm1780387lji.41.2020.07.10.03.33.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jul 2020 03:33:16 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 7095110222B; Fri, 10 Jul 2020 13:33:18 +0300 (+03) Date: Fri, 10 Jul 2020 13:33:18 +0300 From: "Kirill A. Shutemov" To: Alex Shi Cc: Matthew Wilcox , Johannes Weiner , Linux-MM , "linux-kernel@vger.kernel.org" , Hugh Dickins Subject: Re: a question of split_huge_page Message-ID: <20200710103318.bm2gp743lagiajao@box> References: <20200709155002.GF12769@casper.infradead.org> <20200709160750.utl46xvavceuvnom@box> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 10, 2020 at 12:51:58PM +0800, Alex Shi wrote: > > > 在 2020/7/10 上午12:07, Kirill A. Shutemov 写道: > > Right, and it's never got removed from LRU during the split. The tail > > pages have to be added to LRU because they now separate from the tail > > page. > > > According to the explaination, looks like we could remove the code path, > since it's never got into. (base on my v15 patchset). Any comments? Yes. But why? It's reasonable failsafe that gives chance to recover if something goes wrong. -- Kirill A. Shutemov