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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19FA8C433EF for ; Mon, 8 Nov 2021 06:48:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AB0B4610A0 for ; Mon, 8 Nov 2021 06:48:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org AB0B4610A0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 427B96B0081; Mon, 8 Nov 2021 01:48:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3D66A6B0082; Mon, 8 Nov 2021 01:48:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2ED6A6B0083; Mon, 8 Nov 2021 01:48:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0193.hostedemail.com [216.40.44.193]) by kanga.kvack.org (Postfix) with ESMTP id 2090C6B0081 for ; Mon, 8 Nov 2021 01:48:40 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id B5B47180ACC3C for ; Mon, 8 Nov 2021 06:48:39 +0000 (UTC) X-FDA: 78784834758.04.DA2D2FC Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by imf29.hostedemail.com (Postfix) with ESMTP id 08819900067C for ; Mon, 8 Nov 2021 06:48:37 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10161"; a="212219190" X-IronPort-AV: E=Sophos;i="5.87,217,1631602800"; d="scan'208";a="212219190" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2021 22:48:33 -0800 X-IronPort-AV: E=Sophos;i="5.87,217,1631602800"; d="scan'208";a="601311940" Received: from yhuang6-desk2.sh.intel.com (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.239.159.101]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2021 22:48:30 -0800 From: "Huang, Ying" To: Baolin Wang Cc: Dave Hansen , , , , , , , Subject: Re: [RFC PATCH] mm: migrate: Add new node demotion strategy References: <665cb882-6dbc-335f-1435-e52659d7ee58@intel.com> <87tugrxqks.fsf@yhuang6-desk2.ccr.corp.intel.com> <240c5997-ab7e-8045-dacc-1afdb7c49a0d@linux.alibaba.com> <9271f9d7-e251-9ed4-2126-8debb3395891@linux.alibaba.com> Date: Mon, 08 Nov 2021 14:48:28 +0800 In-Reply-To: <9271f9d7-e251-9ed4-2126-8debb3395891@linux.alibaba.com> (Baolin Wang's message of "Mon, 8 Nov 2021 14:38:36 +0800") Message-ID: <87fss7w3b7.fsf@yhuang6-desk2.ccr.corp.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Authentication-Results: imf29.hostedemail.com; dkim=none; spf=none (imf29.hostedemail.com: domain of ying.huang@intel.com has no SPF policy when checking 192.55.52.136) smtp.mailfrom=ying.huang@intel.com; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none) X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 08819900067C X-Stat-Signature: pfj6tc7rxw5wkh763d5rxcpzynmawhcx X-HE-Tag: 1636354117-180476 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: Baolin Wang writes: > On 2021/11/7 23:20, Dave Hansen wrote: >> On 11/7/21 1:33 AM, Baolin Wang wrote: >>> Thanks for your suggestion. After some thinking, can we change the >>> node_demotion[] structure like below? Which means one source node can be >>> demoted to mutiple target node, and we can set up the target node mask >>> according to the node distance. How do you think? Thanks. >>> >>> static nodemask_t node_demotion[MAX_NUMNODES] __read_mostly =3D >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 {[0 ...=C2=A0 MAX_NUMNODES = - 1] =3D NODE_MASK_NONE}; >> How large is that in the worst case? > > For the worst case (MAX_NUMNODES=3D1024), the size of the node_demotion > is 131072 bytes, while the size of original data structure is 4096 > bytes. Maybe we can allocate the node_demotion dynamically? Per my understanding, in most cases, the number of demotion target nodes should be quite small. So why not restrict the number of demotion target nodes to make it some kind of simple array? Best Regards, Huang, Ying