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=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 19E25C433F5 for ; Fri, 7 Sep 2018 08:34:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD1552075B for ; Fri, 7 Sep 2018 08:34:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD1552075B 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 S1728074AbeIGNOq (ORCPT ); Fri, 7 Sep 2018 09:14:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:43390 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725843AbeIGNOq (ORCPT ); Fri, 7 Sep 2018 09:14:46 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 52BBCAC1F; Fri, 7 Sep 2018 08:34:53 +0000 (UTC) Date: Fri, 7 Sep 2018 10:34:52 +0200 From: Michal Hocko To: Shuah Khan 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 Subject: Re: [PATCH] arm64: add NUMA emulation support Message-ID: <20180907083452.GC19621@dhcp22.suse.cz> References: <20180824230559.32336-1-shuah@kernel.org> <20180828174011.GE20375@arm.com> <20180829110802.GD10349@dhcp22.suse.cz> <20180905064252.GW14951@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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. -- Michal Hocko SUSE Labs