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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 86F92C433DF for ; Wed, 24 Jun 2020 11:17:03 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4A0542082F for ; Wed, 24 Jun 2020 11:17:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vYF3X4PN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4A0542082F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C949E6B0003; Wed, 24 Jun 2020 07:17:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C44A56B0005; Wed, 24 Jun 2020 07:17:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B338C6B0007; Wed, 24 Jun 2020 07:17:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0148.hostedemail.com [216.40.44.148]) by kanga.kvack.org (Postfix) with ESMTP id 9C0266B0003 for ; Wed, 24 Jun 2020 07:17:02 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 4FB28180AD801 for ; Wed, 24 Jun 2020 11:17:02 +0000 (UTC) X-FDA: 76963853484.24.cry48_5c12f6326e43 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin24.hostedemail.com (Postfix) with ESMTP id 24C301A4A7 for ; Wed, 24 Jun 2020 11:17:02 +0000 (UTC) X-HE-Tag: cry48_5c12f6326e43 X-Filterd-Recvd-Size: 4726 Received: from mail-qt1-f194.google.com (mail-qt1-f194.google.com [209.85.160.194]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Wed, 24 Jun 2020 11:17:01 +0000 (UTC) Received: by mail-qt1-f194.google.com with SMTP id j10so1300733qtq.11 for ; Wed, 24 Jun 2020 04:17:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=1QyM/HqARorDXEZaotWm9fAdVIrUCV4nTUqtByPEBHY=; b=vYF3X4PNJrFT5ls4obCbDfAPsEBX9lcrho3AXxEdX6mM0zLaaUV6Wt04rXoqeMvzWr JOj7Aouo70Uz8vPSGaJIx+xHzQu/qzKQTlCRZN9QFSMqv6RvNRRQZvucwk5Sp0CuCAu/ yKalJGjnbMG/j0t9v0gndaMWU+PjeKa4GsAqdwjnMWjrRhCsHsCh35aPRSI+LLCEZQaA 2baTl5R61MAO8FrLM94V2rATycUsrGZLhXMkt7DUaTHqgYNibGe9MXR42HZ4ta9rxr9E p3Q+mc+UPPhKSMDohHeZYVwygg7faBPS+TXBOmy/GxGk0u8oq+YSuy7X2aSYPfU4Ui0x r0pA== 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:content-transfer-encoding; bh=1QyM/HqARorDXEZaotWm9fAdVIrUCV4nTUqtByPEBHY=; b=ntLrwz0h6a0lNbk5PIU7qp/SNsNNHjyAKxebBiYu4NHnhp4D9QBM7rSuUN7UjPehsI d+uOvulgkm/YNmc2MLvXjw7ijiHUnJJtvQLyygge+rUVeQm89X7agtip6Nw7B6TxVWKE aD1FQ3Oq+XD/MbpOwA+kulB+9BOMwfi+iUsa5WmEnwUbO2GPPnvnmLD7iybI4C+4NUm4 MQtECmF2eQvRzf/Z0v0pdd2++ifd7oe6vE/JcCdzYcZ8Uf6++jAwSBlxcyJ85zLu00q4 5mFTqrDffPPxssQwnDVE7ddiKAEfE4IetvrsksdJMh7W+Jv0qClt3rjgDg+zh6Sj+qmF zdeQ== X-Gm-Message-State: AOAM530tscAceY1k058qxXlTLyNjmDs5lFzNRtHYpbKnHZvKZQiz5cpO sUVcaZwnbeEjC8C85bGCUtuLgemRcdNF23bSwbY= X-Google-Smtp-Source: ABdhPJwVQLOXz76P4Bkfd0fbs4sSbAiQbiiCnTQocyrRVoSZo2wPjXbuj6H7mWPXRfdqtza+kViSvHDLCp9hFVYi33k= X-Received: by 2002:aed:2e07:: with SMTP id j7mr3802091qtd.338.1592997421053; Wed, 24 Jun 2020 04:17:01 -0700 (PDT) MIME-Version: 1.0 References: <73b5db17-805a-4f1a-60f7-26695c0422e8@redhat.com> In-Reply-To: <73b5db17-805a-4f1a-60f7-26695c0422e8@redhat.com> From: =?UTF-8?B?5a2Z5LiW6b6ZIHN1bnNoaWxvbmc=?= Date: Wed, 24 Jun 2020 19:16:49 +0800 Message-ID: Subject: Re: Are there still some methods that could be used by the Linux kernel to reduce memory fragmentation while both CONFIG-MIGRATION and CONFIG-COMPACTION are disabled? To: David Hildenbrand Cc: linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 24C301A4A7 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Thank you for your attention to this matter. >> Are there still some methods that could be used by the Linux kernel >> to reduce memory fragmentation while both CONFIG-MIGRATION >> and CONFIG-COMPACTION are disabled? > > >We do have mobility grouping on pageblock order. >Also, I think you can use ZONE_MOVABLE without migration and compaction, >to at least locally limit unmovable fragmentation. It's a good news. Could you please explain that in more detail for me or suggest some documen= ts for me to go through. As per the post(http://lkml.iu.edu/hypermail/linux/kernel/1703.1/06782.html= ), I think it's something like ZONE_NORMAL. And I find that "ZONE_MOVEABLE" is available on Linux-v4.9. >> >> Are there some system settings that could make for this goal? > >Why don't you want page compaction/migration? Because I am using a real-time system(and I have to apply a patch to Linux kernel), I have no choice other than disabling these aforementioned options. Is there some potential problems that I should be aware of if I enable "ZONE_MOVABLE" on real-time system? Best Regards. David Hildenbrand =E4=BA=8E2020=E5=B9=B46=E6=9C=8824=E6= =97=A5=E5=91=A8=E4=B8=89 =E4=B8=8B=E5=8D=885:53=E5=86=99=E9=81=93=EF=BC=9A > > On 23.06.20 17:52, =E5=AD=99=E4=B8=96=E9=BE=99 sunshilong wrote: > > Are there still some methods that could be used by the Linux kernel > > to reduce memory fragmentation while both CONFIG-MIGRATION > > and CONFIG-COMPACTION are disabled? > > We do have mobility grouping on pageblock order. > > Also, I think you can use ZONE_MOVABLE without migration and compaction, > to at least locally limit unmovable fragmentation. > > > > > Are there some system settings that could make for this goal? > > Why don't you want page compaction/migration? > > -- > Thanks, > > David / dhildenb >