Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750995AbWHPIB7 (ORCPT ); Wed, 16 Aug 2006 04:01:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750993AbWHPIB7 (ORCPT ); Wed, 16 Aug 2006 04:01:59 -0400 Received: from mailhub.sw.ru ([195.214.233.200]:48569 "EHLO relay.sw.ru") by vger.kernel.org with ESMTP id S1750760AbWHPIB6 (ORCPT ); Wed, 16 Aug 2006 04:01:58 -0400 Message-ID: <44E2D175.1010506@sw.ru> Date: Wed, 16 Aug 2006 12:04:05 +0400 From: Kirill Korotaev User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.13) Gecko/20060417 X-Accept-Language: en-us, en, ru MIME-Version: 1.0 To: "Eric W. Biederman" CC: Alan Cox , containers@lists.osdl.org, linux-kernel@vger.kernel.org, Oleg Nesterov Subject: Re: [Containers] [PATCH 6/7] vt: Update spawnpid to be a struct pid_t References: <1155666193191-git-send-email-ebiederm@xmission.com> <1155667982.24077.307.camel@localhost.localdomain> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1505 Lines: 40 > Alan Cox writes: > > >>Ar Maw, 2006-08-15 am 12:23 -0600, ysgrifennodd Eric W. Biederman: >> >>>This keeps the wrong process from being notified if the >>>daemon to spawn a new console dies. >> >>Not sure why we count pids not task structs but within the proposed >>implementation this appears correct so > > > Basically struct pid is relatively cheap, 64bytes or so. > struct task is expensive 10K or so, when all of the stacks > and everything are included. > > Counting pids allows the task to exit in user space and free up > all of it's memory. > > When /proc used to count the task struct it was fairly easy to > deliberately oom a 32bit machine just by open up directories in > /proc and then having the process exit. rlimits didn't help because > we don't count processes that have exited. hey, hey. your patch doesn't help in this situation (much)! inodes and dentries can still consume much memory. it just makes the situation a bit better. I wonder whether it is easy to have the following done with your implementation: container tasks visible from host. theoretically having 2 pids (vpid, pid) it should be implementable. Do you see any obstacles? in other regards patches look pretty good. Good job! Kirill - 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/