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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 6E04FC2D0D1 for ; Thu, 19 Dec 2019 20:22:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2773B24679 for ; Thu, 19 Dec 2019 20:22:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="u6Wv8j6r" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2773B24679 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B29818E017C; Thu, 19 Dec 2019 15:22:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id ADA4B8E00F5; Thu, 19 Dec 2019 15:22:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9A1E08E017C; Thu, 19 Dec 2019 15:22:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0221.hostedemail.com [216.40.44.221]) by kanga.kvack.org (Postfix) with ESMTP id 8227C8E00F5 for ; Thu, 19 Dec 2019 15:22:15 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 52EB052B7 for ; Thu, 19 Dec 2019 20:22:15 +0000 (UTC) X-FDA: 76283013030.04.pull86_880d53f985154 X-HE-Tag: pull86_880d53f985154 X-Filterd-Recvd-Size: 4112 Received: from mail-qk1-f194.google.com (mail-qk1-f194.google.com [209.85.222.194]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Thu, 19 Dec 2019 20:22:14 +0000 (UTC) Received: by mail-qk1-f194.google.com with SMTP id x129so5724845qke.8 for ; Thu, 19 Dec 2019 12:22:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=r3E/D07/ZPDWwCmYCAV3wbix4nrV2NEeuAgSXWyKjuk=; b=u6Wv8j6rmYawNkXdt1PMu7j72pvZx7svOC3E6pznjHc7+FKrdLbnpmSkSLwC619uwG SIgEtVQR3RNyDP+MnUu66RibgcVwqQX/7rUtScjLHr6Pal8yn5U7QlcAesErCFSx45hg onib1uCCGQGQadOVJ+9ENHyQPk7xutFYx7b1zOF5X0rBodDabJl+LlsmlqIuIykD/DzO MOmBK1o41B4picUTKElrG4ixXSjCjS7NnbUTWFBfd3+qZfRpJHnl1AFp7qvXMZxle2rU 17vEUZKBjvL3LIfCGY1R9UbjtXkIr9KX9urMGHHKJB+HfnE4pxaih6aOzIYdxGCeXAuG GRzw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=r3E/D07/ZPDWwCmYCAV3wbix4nrV2NEeuAgSXWyKjuk=; b=TzIuD7wiHqtpqjtZ9VeVGhBc3DFSvrnDQviC4Ny3PLSCE4ncY1GiP2vVlVOwVa24Er 1uKBj2IkyjEmbs8kCZ82mhCwSfGzh/QdWWhStWp77AUIH/FOCCo2zsp1N9NLqpT7BflJ cYkA06eYzSuunaTCsXcgQmxXApvNw00xgZxpRuHRoivRdcCkQALkF/hKRhOYWXKLPV6U ZyqwPok87C4MkScOPlFLlkEi0YWzSBVuHzCH8ln8VAuhOMM1zYsYZtx0U9Vih56GcVUh Elqg7l8gvAvLkrj0MB1vYU6fBS4xJeuozPWVbYtNvRYecA45bIZjIn832Lc0wmxv8fC3 ZGdQ== X-Gm-Message-State: APjAAAXN5CD2gR8xBVYuJHw+fm3k7+awjtuIEhQ0i42JUPLlWZADJBPV qA7XD5V4gIn2huosOVMVQ+g= X-Google-Smtp-Source: APXvYqwjzlfu4HM0DKELI9BComNmyS8fALsw5Qp8Q5/Hv7wFJLwaM5FyiCgJ4C2p0Cv1SU6/gb4l9w== X-Received: by 2002:a37:de05:: with SMTP id h5mr10251127qkj.474.1576786934078; Thu, 19 Dec 2019 12:22:14 -0800 (PST) Received: from localhost ([2620:10d:c091:500::1:29ea]) by smtp.gmail.com with ESMTPSA id z28sm2280778qtz.69.2019.12.19.12.22.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 19 Dec 2019 12:22:13 -0800 (PST) Date: Thu, 19 Dec 2019 12:22:11 -0800 From: Tejun Heo To: Johannes Weiner Cc: Andrew Morton , Roman Gushchin , Michal Hocko , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH v2 0/3] mm: memcontrol: recursive memory protection Message-ID: <20191219202211.GD2914998@devbig004.ftw2.facebook.com> References: <20191219200718.15696-1-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191219200718.15696-1-hannes@cmpxchg.org> User-Agent: Mutt/1.5.21 (2010-09-15) 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 Thu, Dec 19, 2019 at 03:07:15PM -0500, Johannes Weiner wrote: > Changes since v1: > - improved Changelogs based on the discussion with Roman. Thanks! > - fix div0 when recursive & fixed protection is combined > - fix an unused compiler warning > > The current memory.low (and memory.min) semantics require protection > to be assigned to a cgroup in an untinterrupted chain from the > top-level cgroup all the way to the leaf. > > In practice, we want to protect entire cgroup subtrees from each other > (system management software vs. workload), but we would like the VM to > balance memory optimally *within* each subtree, without having to make > explicit weight allocations among individual components. The current > semantics make that impossible. Acked-by: Tejun Heo The original behavior turned out to be a significant source of mistakes and use cases which would require older behavior just weren't there. Thanks. -- tejun