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 71AC2C433F5 for ; Mon, 8 Nov 2021 02:12:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DE3C86134F for ; Mon, 8 Nov 2021 02:12:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org DE3C86134F 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 09E866B00A8; Sun, 7 Nov 2021 21:12:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 04D796B00A9; Sun, 7 Nov 2021 21:12:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E7F056B00AD; Sun, 7 Nov 2021 21:12:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0054.hostedemail.com [216.40.44.54]) by kanga.kvack.org (Postfix) with ESMTP id D6C906B00A8 for ; Sun, 7 Nov 2021 21:12:14 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 887DE78341 for ; Mon, 8 Nov 2021 02:12:14 +0000 (UTC) X-FDA: 78784138188.17.C020F47 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf25.hostedemail.com (Postfix) with ESMTP id DDA1AB0001BB for ; Mon, 8 Nov 2021 02:12:02 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10161"; a="292978916" X-IronPort-AV: E=Sophos;i="5.87,217,1631602800"; d="scan'208";a="292978916" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2021 18:12:11 -0800 X-IronPort-AV: E=Sophos;i="5.87,217,1631602800"; d="scan'208";a="502813869" 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; 07 Nov 2021 18:12:09 -0800 From: "Huang, Ying" To: Dave Hansen Cc: Baolin Wang , , , , , , , 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> Date: Mon, 08 Nov 2021 10:12:06 +0800 In-Reply-To: (Dave Hansen's message of "Fri, 5 Nov 2021 08:47:23 -0700") Message-ID: <877ddjxuo9.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: DDA1AB0001BB X-Stat-Signature: hbfdbobopk17ompdtz1rkego93w5cs9n Authentication-Results: imf25.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf25.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: 1636337522-586283 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: Dave Hansen writes: > On 11/4/21 7:51 PM, Huang, Ying wrote: >>> Let's also try to do it with the existing node_demotion[] data >>> structure before we go adding more. >> To avoid cache ping-pong, I guess some kind of per-CPU data structure >> may be more suitable for interleaving among multiple nodes. > > It would probably be better to just find something that's more > read-heavy. Like, instead of keeping a strict round-robin, just > randomly select one of the notes to which you can round-robin. > > That will scale naturally without having to worry about caching or fancy > per-cpu data structures. Yes. That sounds good. And per-CPU data structure is used inside random API too :-) Best Regards, Huang, Ying