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=-1.0 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 1CF02C4321E for ; Fri, 7 Sep 2018 22:31:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B73B920844 for ; Fri, 7 Sep 2018 22:31:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B73B920844 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726634AbeIHDOT (ORCPT ); Fri, 7 Sep 2018 23:14:19 -0400 Received: from mailout.easymail.ca ([64.68.200.34]:60001 "EHLO mailout.easymail.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726354AbeIHDOT (ORCPT ); Fri, 7 Sep 2018 23:14:19 -0400 Received: from localhost (localhost [127.0.0.1]) by mailout.easymail.ca (Postfix) with ESMTP id 96EA721917; Fri, 7 Sep 2018 22:31:11 +0000 (UTC) Received: from mailout.easymail.ca ([127.0.0.1]) by localhost (emo02-pco.easydns.vpn [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id IFMjJtrk8YZq; Fri, 7 Sep 2018 22:31:11 +0000 (UTC) Received: from [192.168.1.87] (c-24-9-64-241.hsd1.co.comcast.net [24.9.64.241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mailout.easymail.ca (Postfix) with ESMTPSA id AFB76218F1; Fri, 7 Sep 2018 22:31:00 +0000 (UTC) Subject: Re: [PATCH] arm64: add NUMA emulation support To: Michal Hocko Cc: Will Deacon , catalin.marinas@arm.com, sudeep.holla@arm.com, ganapatrao.kulkarni@cavium.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Shuah Khan References: <20180824230559.32336-1-shuah@kernel.org> <20180828174011.GE20375@arm.com> <20180829110802.GD10349@dhcp22.suse.cz> <20180905064252.GW14951@dhcp22.suse.cz> <20180907083452.GC19621@dhcp22.suse.cz> From: Shuah Khan Message-ID: Date: Fri, 7 Sep 2018 16:30:59 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180907083452.GC19621@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/07/2018 02:34 AM, Michal Hocko wrote: > On Thu 06-09-18 15:53:34, Shuah Khan wrote: > [...] >> A few critical allocations could be satisfied and root cgroup prevails. It is not the >> intent to have exclusivity at the expense of the kernel. > > Well, it is not "few critical allocations". It can be a lot of > memory. Basically any GFP_KERNEL allocation. So how exactly you expect > this to work when you cannot estimate how much > memory will kernel eat? > >> >> This feature will allow a way to configure cpusets on non-NUMA for workloads that can >> benefit from the reservation and isolation that is available within the constraints of >> exclusive cpuset policies. > > AFAIR this was the first approach Google took for the memory isolation > and they moved over to memory cgroups. In addition to isolation, being able to reserve a block instead is one of the issues I am looking to address. Unfortunately memory cgroups won't address that issue. I would recommend to talk to > those guys bebfore you introduce potentially a lot of code that will not > really work for the workload you indend it for. > Will you be able to point me to a good contact at Goggle and/or some pointers on finding discussion on the memory isolation. My searches on lkml came up short, thanks, -- Shuah