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 97D61C433EF for ; Mon, 8 Nov 2021 08:15:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2351B6120D for ; Mon, 8 Nov 2021 08:15:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2351B6120D 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 AF1796B006C; Mon, 8 Nov 2021 03:15:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AA1D76B0078; Mon, 8 Nov 2021 03:15:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 990666B007D; Mon, 8 Nov 2021 03:15:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 866536B006C for ; Mon, 8 Nov 2021 03:15:10 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 36BD01839C9BC for ; Mon, 8 Nov 2021 08:15:10 +0000 (UTC) X-FDA: 78785052738.27.E210DDB Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf02.hostedemail.com (Postfix) with ESMTP id 1900B700177B for ; Mon, 8 Nov 2021 08:15:02 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10161"; a="293015548" X-IronPort-AV: E=Sophos;i="5.87,218,1631602800"; d="scan'208";a="293015548" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Nov 2021 00:15:07 -0800 X-IronPort-AV: E=Sophos;i="5.87,218,1631602800"; d="scan'208";a="502915910" Received: from yhuang6-desk2.sh.intel.com (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.239.159.101]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Nov 2021 00:15:04 -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> <87fss7w3b7.fsf@yhuang6-desk2.ccr.corp.intel.com> Date: Mon, 08 Nov 2021 16:12:10 +0800 In-Reply-To: (Baolin Wang's message of "Mon, 8 Nov 2021 15:07:18 +0800") Message-ID: <87sfw7ukv9.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=ascii X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 1900B700177B X-Stat-Signature: y7nt4bt8aiij4xsdhepeqzqktxa7c9kk Authentication-Results: imf02.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf02.hostedemail.com: domain of ying.huang@intel.com has no SPF policy when checking 134.134.136.31) smtp.mailfrom=ying.huang@intel.com X-HE-Tag: 1636359302-100079 Content-Transfer-Encoding: quoted-printable 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 2021/11/8 14:48, Huang, Ying writes: >> Baolin Wang writes: >>=20 >>> 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 c= an be >>>>> demoted to mutiple target node, and we can set up the target node m= ask >>>>> according to the node distance. How do you think? Thanks. >>>>> >>>>> static nodemask_t node_demotion[MAX_NUMNODES] __read_mostly =3D >>>>> =A0=A0=A0 {[0 ... 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_demoti= on >>> 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? > > Yes, agree. Something like below is reasonable for you? > > #define DEMOTION_TARGET_NODES 16 > typedef struct { DECLARE_BITMAP(bits, DEMOTION_TARGET_NODES); } > demotemask_t; > > static demotemask_t node_demotion[MAX_NUMNODES]; I don't think we need a bitmap. May be something as following, #define DEMOTION_TARGET_NODES 15 struct demotion_nodes { unsigned short nr; unsigned short nodes[DEMOTION_TARGET_NODES]; }; Best Regards, Huang, Ying