Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752305AbbKPUlT (ORCPT ); Mon, 16 Nov 2015 15:41:19 -0500 Received: from mail-oi0-f48.google.com ([209.85.218.48]:35170 "EHLO mail-oi0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751394AbbKPUlQ (ORCPT ); Mon, 16 Nov 2015 15:41:16 -0500 MIME-Version: 1.0 In-Reply-To: <1447703505-29672-1-git-send-email-serge@hallyn.com> References: <1447703505-29672-1-git-send-email-serge@hallyn.com> Date: Mon, 16 Nov 2015 21:41:15 +0100 Message-ID: Subject: Re: CGroup Namespaces (v4) From: Richard Weinberger To: "Serge E. Hallyn" Cc: LKML , "open list:ABI/API" , Linux Containers , "Eric W. Biederman" , LXC development mailing-list , Tejun Heo , cgroups mailinglist , Andrew Morton Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1623 Lines: 46 Serge, On Mon, Nov 16, 2015 at 8:51 PM, wrote: > To summarize the semantics: > > 1. CLONE_NEWCGROUP re-uses 0x02000000, which was previously CLONE_STOPPED > > 2. unsharing a cgroup namespace makes all your current cgroups your new > cgroup root. > > 3. /proc/pid/cgroup always shows cgroup paths relative to the reader's > cgroup namespce root. A task outside of your cgroup looks like > > 8:memory:/../../.. > > 4. when a task mounts a cgroupfs, the cgroup which shows up as root depends > on the mounting task's cgroup namespace. > > 5. setns to a cgroup namespace switches your cgroup namespace but not > your cgroups. > > With this, using github.com/hallyn/lxc #2015-11-09/cgns (and > github.com/hallyn/lxcfs #2015-11-10/cgns) we can start a container in a full > proper cgroup namespace, avoiding either cgmanager or lxcfs cgroup bind mounts. > > This is completely backward compatible and will be completely invisible > to any existing cgroup users (except for those running inside a cgroup > namespace and looking at /proc/pid/cgroup of tasks outside their > namespace.) > cgroupns-root. IIRC one downside of this series was that only the new "sane" cgroup layout was supported and hence it was useless for everything which expected the default layout. Hence, still no systemd for us. :) Is this now different? -- Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/