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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 C1833C04EBF for ; Mon, 23 Sep 2019 13:28:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A22E20867 for ; Mon, 23 Sep 2019 13:28:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569245313; bh=MK+c5c98R3mKB/oVI11sCbJay3/hNsknO37B6y6Lchs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=amMIG2cuAx8M2wnx4S/S11gjWus+wCKdxy0XZs/hPmldDjAXnXmoHkVoot8I6hWLv uADyTZpBanZ6MtNeNSJiPTrycMzcGt6iMZVI+wCTCFvr73AGTac2TEilIlh0BOxTNQ RpQompQAdFs6JTepOQh9RU7bFxyWkCmxseSnbRgU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407085AbfIWN2c (ORCPT ); Mon, 23 Sep 2019 09:28:32 -0400 Received: from mx2.suse.de ([195.135.220.15]:41904 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2405044AbfIWN2c (ORCPT ); Mon, 23 Sep 2019 09:28:32 -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 DE0C5B152; Mon, 23 Sep 2019 13:28:30 +0000 (UTC) Date: Mon, 23 Sep 2019 15:28:30 +0200 From: Michal Hocko To: Hillf Danton Cc: Johannes Weiner , Andrew Morton , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Shakeel Butt , Roman Gushchin , Matthew Wilcox Subject: Re: [RFC] mm: memcg: add priority for soft limit reclaiming Message-ID: <20190923132830.GQ6016@dhcp22.suse.cz> References: <20190919133222.GD15782@dhcp22.suse.cz> <20190923130459.11072-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190923130459.11072-1-hdanton@sina.com> 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 Mon 23-09-19 21:04:59, Hillf Danton wrote: > > On Thu, 19 Sep 2019 21:32:31 +0800 Michal Hocko wrote: > > > > On Thu 19-09-19 21:13:32, Hillf Danton wrote: > > > > > > Currently memory controler is playing increasingly important role in > > > how memory is used and how pages are reclaimed on memory pressure. > > > > > > In daily works memcg is often created for critical tasks and their pre > > > configured memory usage is supposed to be met even on memory pressure. > > > Administrator wants to make it configurable that the pages consumed by > > > memcg-B can be reclaimed by page allocations invoked not by memcg-A but > > > by memcg-C. > > > > I am not really sure I understand the usecase well but this sounds like > > what memory reclaim protection in v2 is aiming at. > > Please describe the usecase. > A tipoint to the v2 stuff please. Documentation/admin-guide/cgroup-v2.rst > > > That configurability is addressed by adding priority for soft limit > > > reclaiming to make sure that no pages will be reclaimed from memcg of > > > higer priortiy in favor of memcg of lower priority. > > > > cgroup v1 interfaces are generally frozen and mostly aimed at backward > > compatibility. I am especially concerned about adding a new way to > > control soft limit which is known to be misdesigned and unfixable to > > behave reasonably. > > > An URL to the drafts/works about the new way in your git tree. Whut? -- Michal Hocko SUSE Labs