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=-3.7 required=3.0 tests=BAYES_00, 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 9A64CC2D0A3 for ; Fri, 6 Nov 2020 15:55:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 05B5022203 for ; Fri, 6 Nov 2020 15:55:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 05B5022203 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 03BAF6B005C; Fri, 6 Nov 2020 10:55:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F2E316B005D; Fri, 6 Nov 2020 10:55:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DA86E6B0068; Fri, 6 Nov 2020 10:55:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0229.hostedemail.com [216.40.44.229]) by kanga.kvack.org (Postfix) with ESMTP id AE06D6B005C for ; Fri, 6 Nov 2020 10:55:09 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 48E81180AD820 for ; Fri, 6 Nov 2020 15:55:09 +0000 (UTC) X-FDA: 77454442338.11.verse95_100d571272d3 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin11.hostedemail.com (Postfix) with ESMTP id 28960180F8B81 for ; Fri, 6 Nov 2020 15:55:09 +0000 (UTC) X-HE-Tag: verse95_100d571272d3 X-Filterd-Recvd-Size: 5247 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Fri, 6 Nov 2020 15:55:06 +0000 (UTC) IronPort-SDR: dEITzff42cPBj+VlbtMtpywZZ2t3EEDpwfc3aWq1OC5V7Rnqzr/NL2oGwJu6D2WrwbMiAeboot YzpC++qrisaQ== X-IronPort-AV: E=McAfee;i="6000,8403,9797"; a="166970503" X-IronPort-AV: E=Sophos;i="5.77,456,1596524400"; d="scan'208";a="166970503" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Nov 2020 07:55:05 -0800 IronPort-SDR: tDj4OyVIr9tk9Jtb24z9upN02k6+2l9N5E3bn+CjQVK86EYvuJOEAKrf0fz4kpJP9s3z3c/+mg yEaWMJRkQYcw== X-IronPort-AV: E=Sophos;i="5.77,456,1596524400"; d="scan'208";a="472104901" Received: from rseth-mobl2.amr.corp.intel.com (HELO intel.com) ([10.252.131.79]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Nov 2020 07:55:04 -0800 Date: Fri, 6 Nov 2020 07:55:03 -0800 From: Ben Widawsky To: "Huang, Ying" Cc: Mel Gorman , Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Ingo Molnar , Rik van Riel , Johannes Weiner , "Matthew Wilcox (Oracle)" , Dave Hansen , Andi Kleen , Michal Hocko , David Rientjes Subject: Re: [PATCH -V2 2/2] autonuma: Migrate on fault among multiple bound nodes Message-ID: <20201106155503.nkwuxr5mkneggzl7@intel.com> Mail-Followup-To: "Huang, Ying" , Mel Gorman , Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Ingo Molnar , Rik van Riel , Johannes Weiner , "Matthew Wilcox (Oracle)" , Dave Hansen , Andi Kleen , Michal Hocko , David Rientjes References: <20201028023411.15045-1-ying.huang@intel.com> <20201028023411.15045-3-ying.huang@intel.com> <20201102111717.GB3306@suse.de> <87eel9wumd.fsf@yhuang-dev.intel.com> <20201105112523.GQ3306@suse.de> <87v9ejosec.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87v9ejosec.fsf@yhuang-dev.intel.com> 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: On 20-11-06 15:28:59, Huang, Ying wrote: > Mel Gorman writes: > > > On Wed, Nov 04, 2020 at 01:36:58PM +0800, Huang, Ying wrote: > >> But from another point of view, I suggest to remove the constraints of > >> MPOL_F_MOF in the future. If the overhead of AutoNUMA isn't acceptable, > >> why not just disable AutoNUMA globally via sysctl knob? > >> > > > > Because it's a double edged sword. NUMA Balancing can make a workload > > faster while still incurring more overhead than it should -- particularly > > when threads are involved rescanning the same or unrelated regions. > > Global disabling only really should happen when an application is running > > that is the only application on the machine and has full NUMA awareness. > > Got it. So NUMA Balancing may in generally benefit some workloads but > hurt some other workloads on one machine. So we need a method to > enable/disable NUMA Balancing for one workload. Previously, this is > done via the explicit NUMA policy. If some explicit NUMA policy is > specified, NUMA Balancing is disabled for the memory region or the > thread. And this can be reverted again for a memory region via > MPOL_MF_LAZY. It appears that we lacks MPOL_MF_LAZY for the thread yet. > > >> > It might still end up being better but I was not aware of a > >> > *realistic* workload that binds to multiple nodes > >> > deliberately. Generally I expect if an application is binding, it's > >> > binding to one local node. > >> > >> Yes. It's not popular configuration for now. But for the memory > >> tiering system with both DRAM and PMEM, the DRAM and PMEM in one socket > >> will become 2 NUMA nodes. To avoid too much cross-socket memory > >> accessing, but take advantage of both the DRAM and PMEM, the workload > >> can be bound to 2 NUMA nodes (DRAM and PMEM). > >> > > > > Ok, that may lead to unpredictable performance as it'll have variable > > performance with limited control of the "important" applications that > > should use DRAM over PMEM. That's a long road but the step is not > > incompatible with the long-term goal. > > Yes. Ben Widawsky is working on a patchset to make it possible to > prefer the remote DRAM instead of the local PMEM as follows, > > https://lore.kernel.org/linux-mm/20200630212517.308045-1-ben.widawsky@intel.com/ > > Best Regards, > Huang, Ying > Rebased version was posted here: https://lore.kernel.org/linux-mm/20201030190238.306764-1-ben.widawsky@intel.com/ Thanks. Ben