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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 AFA34C433DB for ; Wed, 13 Jan 2021 11:04:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 668D422A83 for ; Wed, 13 Jan 2021 11:04:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727561AbhAMLEl (ORCPT ); Wed, 13 Jan 2021 06:04:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726964AbhAMLEk (ORCPT ); Wed, 13 Jan 2021 06:04:40 -0500 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 976EDC061575 for ; Wed, 13 Jan 2021 03:04:00 -0800 (PST) Received: by mail-pf1-x42c.google.com with SMTP id m6so1001570pfm.6 for ; Wed, 13 Jan 2021 03:04:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=vq0sIowdqwCy9ipBvQmxiVHT6coiYZ3i+NvaIZ45Kq8=; b=nNNuIxA8Zxb5hbY0dGnCfyTJ3sc3lW+PoG3W/0Kn8axCab7hhhojw4MbztYBa7UcdX vIFyyqhzjBr7ZUwfkfkz4UkNmiydfJ6qLbxpAjmpMRlCWQeEk5LKTk50D+pBxFBF2uw7 /4TFsvAf76lqDypT4xR5Ih1h5usJYuZ30f9b42Apiktc7u6kMuqAQ9qk13Vafe9y6t3o 55zky9/snLZByYPZ1ObmtYpdNb1jCET5se6kdCOZB9+6tmbh4/URWMQ9r75kAt0cYJAO muJWJS1rZR6AbkYUYWSGJ3mpfL4FZGi+SJG93HgyRJ6tHS2EYtaGtRceh9FwxMl0Gff9 Y1+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=vq0sIowdqwCy9ipBvQmxiVHT6coiYZ3i+NvaIZ45Kq8=; b=DvNucXe6pSyzA7IdSEd3RHqy9Al8TvI62PMDBYXcZ8FXtNiYZ/oeT+xQwpEu32cAPU 9nzGhehZ0qkFlD6w+rd9QJG1CWPXU/JPuo4CUdQJphc7jjWOl9Cwvosts+mU7TVw9ht7 uac+ukOj0hBMf8hTQbOucF+SI08petdpNRxXhdl+hMTgpumCSu+FswQLIuMvlZjUuzHJ 6fb/jzUNq/i3cEji/8csvXRdD2uRT0I1IGLTcLnyrwCxdcgNinrSRZ3oO3k5YGFiYd4i K2CmLLRtBZOXSKAhAyqAuaGNAJuKwiLIVW/YXYTozN5vNvp4a8XqvhsT/wffTGw/F1oL EFlw== X-Gm-Message-State: AOAM532zGwqe+SXuOXRzcCyZXPBQj5dtUjyBqdym/Unj2bYqR3ienhJc XKXGzkBmufwk33vLsxVlpryLoIvzOKgBrXty2ZEANw== X-Google-Smtp-Source: ABdhPJyn+jUaco2N/T1+7oLFKfPMaFPzzCfwa/Phoij/8DTFE73bZ00WKAtENC2GHM3mKzUcgeQr23uxu9JK2Qhrb6o= X-Received: by 2002:a63:1f21:: with SMTP id f33mr1589804pgf.31.1610535840163; Wed, 13 Jan 2021 03:04:00 -0800 (PST) MIME-Version: 1.0 References: <20210113052209.75531-1-songmuchun@bytedance.com> <20210113052209.75531-2-songmuchun@bytedance.com> <20210113105657.GA26599@linux> In-Reply-To: <20210113105657.GA26599@linux> From: Muchun Song Date: Wed, 13 Jan 2021 19:03:21 +0800 Message-ID: Subject: Re: [External] Re: [PATCH v4 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one To: Oscar Salvador Cc: Mike Kravetz , Andrew Morton , Naoya Horiguchi , Andi Kleen , mhocko@suse.cz, Linux Memory Management List , LKML , Yang Shi , Michal Hocko Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 13, 2021 at 6:57 PM Oscar Salvador wrote: > > On Wed, Jan 13, 2021 at 01:22:04PM +0800, Muchun Song wrote: > > diff --git a/mm/migrate.c b/mm/migrate.c > > index 4385f2fb5d18..a6631c4eb6a6 100644 > > --- a/mm/migrate.c > > +++ b/mm/migrate.c > > @@ -1279,6 +1279,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, > > return -ENOSYS; > > } > > > > + if (page_count(hpage) == 1) { > > + /* page was freed from under us. So we are done. */ > > + putback_active_hugepage(hpage); > > + return MIGRATEPAGE_SUCCESS; > > + } > > + > > I was a bit puzzled as why we did not go to the "goto" block that already does > this, but then I saw the put_new_page/new_hpage handlind further down. > It could be re-arranged but out of scope, so: Agree. I also thought about this. :) > > Reviewed-by: Oscar Salvador > Thanks. > > -- > Oscar Salvador > SUSE L3