From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e34.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id m9M32jjW014206 for ; Tue, 21 Oct 2008 23:02:46 -0400 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id m9M32juI145964 for ; Tue, 21 Oct 2008 21:02:45 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m9M32jWN030462 for ; Tue, 21 Oct 2008 21:02:45 -0600 Subject: Re: [RFC v7][PATCH 2/9] General infrastructure for checkpoint restart From: Dave Hansen In-Reply-To: <20081022025513.GA7504@caradoc.them.org> 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> Content-Type: text/plain Date: Tue, 21 Oct 2008 20:02:43 -0700 Message-Id: <1224644563.1848.232.camel@nimitz> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Daniel Jacobowitz Cc: Oren Laadan , linux-api@vger.kernel.org, containers@lists.linux-foundation.org, mingo@elte.hu, linux-kernel@vger.kernel.org, linux-mm@kvack.org, viro@zeniv.linux.org.uk, hpa@zytor.com, Andrew Morton , torvalds@linux-foundation.org, tglx@linutronix.de List-ID: 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, 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