From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [RFC v7][PATCH 2/9] General infrastructure for checkpoint restart Date: Tue, 21 Oct 2008 20:02:43 -0700 Message-ID: <1224644563.1848.232.camel@nimitz> References: <1224481237-4892-1-git-send-email-orenl@cs.columbia.edu> <1224481237-4892-3-git-send-email-orenl@cs.columbia.edu> <20081021124130.a002e838.akpm@linux-foundation.org> <20081021202410.GA10423@us.ibm.com> <48FE82DF.6030005@cs.columbia.edu> <20081022025513.GA7504@caradoc.them.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20081022025513.GA7504-FDxGpBj5bhMn2ysHARXsoQ@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Daniel Jacobowitz Cc: Oren Laadan , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, mingo-X9Un+BFzKDI@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, Andrew Morton , torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org List-Id: linux-api@vger.kernel.org On Tue, 2008-10-21 at 22:55 -0400, Daniel Jacobowitz wrote: > I haven't been following - but why this whole container restriction? > Checkpoint/restart of individual processes is very useful too. > There are issues with e.g. IPC, but I'm not convinced they're > substantially different than the issues already present for a > container. Containers provide isolation. Once you have isolation, you have a discrete set of resources which you can checkpoint/restart. Let's say you have a process you want to checkpoint. If it uses a completely discrete IPC namespace, you *know* that nothing else depends on those IPC ids. We don't even have to worry about who might have been using them and when. Also think about pids. Without containers, how can you guarantee a restarted process that it can regain the same pid? -- Dave -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html