From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: user-cr: Extra unshare() calls ? Date: Mon, 8 Mar 2010 14:58:51 -0600 Message-ID: <20100308205851.GB21490@us.ibm.com> References: <20100308201338.GA16446@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20100308201338.GA16446-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Sukadev Bhattiprolu Cc: Containers List-Id: containers.vger.kernel.org Quoting Sukadev Bhattiprolu (sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org): > > Came across this while testing LXC. > > > 1. Does ckpt_remount_proc() need to unshare() ? Or can we have the > clone() that calls __ckpt_coordinator() clone with CLONE_NEWNS|CLONE_FS > instead ? > > The problem with the unshare() in ckpt_remount_proc() is that it > creates an extra level in cgroup hierarchy (see below) after restart. > So applications expecting the cgroup hierarchy before chckpoint will > be surprised. > > 2. When --mount-pty (or --mntns) is specified, do we need to unshare() > in the parent process ? Considering only the full-container restart > for now (ignore self-restart and subtree restart), can we just > specify (CLONE_NEWNS|CLONE_FS) at the time of creating the first > restarted process ? And then move remounting of devpts into ckpt_remount_proc() called from __ckpt_coordinator() as well? -serge