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 EF496C433F5 for ; Fri, 5 Nov 2021 02:52:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8512E611CE for ; Fri, 5 Nov 2021 02:52:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 8512E611CE 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 F046B6B006C; Thu, 4 Nov 2021 22:52:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EB19B940007; Thu, 4 Nov 2021 22:52:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D78E26B0073; Thu, 4 Nov 2021 22:52:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0057.hostedemail.com [216.40.44.57]) by kanga.kvack.org (Postfix) with ESMTP id C86E36B006C for ; Thu, 4 Nov 2021 22:52:08 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 853DB74D1F for ; Fri, 5 Nov 2021 02:52:08 +0000 (UTC) X-FDA: 78773352336.22.6DE4101 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf12.hostedemail.com (Postfix) with ESMTP id BFDA010000B9 for ; Fri, 5 Nov 2021 02:51:37 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10158"; a="212579923" X-IronPort-AV: E=Sophos;i="5.87,210,1631602800"; d="scan'208";a="212579923" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Nov 2021 19:51:36 -0700 X-IronPort-AV: E=Sophos;i="5.87,210,1631602800"; d="scan'208";a="501791069" 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; 04 Nov 2021 19:51:33 -0700 From: "Huang, Ying" To: Dave Hansen , Baolin Wang Cc: , , , , , , Subject: Re: [RFC PATCH] mm: migrate: Add new node demotion strategy References: <665cb882-6dbc-335f-1435-e52659d7ee58@intel.com> Date: Fri, 05 Nov 2021 10:51:31 +0800 In-Reply-To: <665cb882-6dbc-335f-1435-e52659d7ee58@intel.com> (Dave Hansen's message of "Thu, 4 Nov 2021 08:18:02 -0700") Message-ID: <87tugrxqks.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: BFDA010000B9 X-Stat-Signature: jbrcja3ei83e3zio3o7pz55tkrqafbjx Authentication-Results: imf12.hostedemail.com; dkim=none; spf=none (imf12.hostedemail.com: domain of ying.huang@intel.com has no SPF policy when checking 192.55.52.151) smtp.mailfrom=ying.huang@intel.com; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none) X-HE-Tag: 1636080697-598912 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 2:13 AM, Baolin Wang wrote: >> +What: /sys/kernel/mm/numa/demotion_mode >> +Date: November 2021 >> +Contact: Linux memory management mailing list >> +Description: Set the demotion mode when enabling demoting pages during reclaim > > I don't think we need a tunable for this. The existing behavior is just > stupid for your hardware and can be replaced. Yes. I think so too. I don't think DIRECT_DEMOTION is reasonable for your system. > 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. Best Regards, Huang, Ying