From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cedric Le Goater Subject: Re: How much of a mess does OpenVZ make? ;) Was: What can OpenVZ do? Date: Fri, 13 Mar 2009 17:53:57 +0100 Message-ID: <49BA8FA5.5030003@free.fr> References: <1234467035.3243.538.camel@calx> <20090212114207.e1c2de82.akpm@linux-foundation.org> <1234475483.30155.194.camel@nimitz> <20090212141014.2cd3d54d.akpm@linux-foundation.org> <1234479845.30155.220.camel@nimitz> <20090226155755.GA1456@x200.localdomain> <20090310215305.GA2078@x200.localdomain> <49B775B4.1040800@free.fr> <20090312145311.GC12390@us.ibm.com> <49BA8013.3030103@free.fr> <20090313163531.GA10685@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090313163531.GA10685@us.ibm.com> Sender: owner-linux-mm@kvack.org To: "Serge E. Hallyn" Cc: Alexey Dobriyan , linux-api@vger.kernel.org, containers@lists.linux-foundation.org, hpa@zytor.com, linux-kernel@vger.kernel.org, Dave Hansen , linux-mm@kvack.org, viro@zeniv.linux.org.uk, mingo@elte.hu, mpm@selenic.com, tglx@linutronix.de, torvalds@linux-foundation.org, Andrew Morton , xemul@openvz.org List-Id: linux-api@vger.kernel.org Serge E. Hallyn wrote: > Quoting Cedric Le Goater (legoater@free.fr): >>> No, what you're suggesting does not suffice. >> probably. I'm still trying to understand what you mean below :) >> >> Man, I hate these hierarchicals pid_ns. one level would have been enough, >> just one vpid attribute in 'struct pid*' > > Well I don't mind - temporarily - saying that nested pid namespaces > are not checkpointable. It's just that if we're going to need a new > syscall anyway, then why not go ahead and address the whole problem? > It's not hugely more complicated, and seems worth it. yes. agree. there's a thread going on that topic. i'm following it. [ ... ] >> anyway, I think that some CLONE_NEW* should be forbidden. Daniel should >> send soon a little patch for the ns_cgroup restricting the clone flags >> being used in a container. > > Uh, that feels a bit over the top. We want to make this > uncheckpointable (if it remains so), not prevent the whole action. > After all I may be running a container which I don't plan on ever > checkpointing, and inside that container running a job which i do > want to migrate. ok. i've been scanning the emails a bit fast. that would be fine and useful. > So depending on if we're doing the Dave or the rest-of-the-world > way :), we either clear_bit(pidns->may_checkpoint) on the parent > pid_ns when a child is created, or we walk every task being > checkpointed and make sure they each are in the same pid_ns. > Doesn't that suffice? yes. this 'may_checkpoint' is a container level info so I wonder where you store it. in a cgroup_checkpoint ? sorry for jumping in and may be restarting some old topics of discussion. C. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org