From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751382AbWDIGHR (ORCPT ); Sun, 9 Apr 2006 02:07:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751416AbWDIGHR (ORCPT ); Sun, 9 Apr 2006 02:07:17 -0400 Received: from mx1.suse.de ([195.135.220.2]:39611 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751382AbWDIGHP (ORCPT ); Sun, 9 Apr 2006 02:07:15 -0400 From: Andi Kleen To: "Serge E. Hallyn" Subject: Re: [RFC][PATCH 1/5] uts namespaces: Implement utsname namespaces Date: Sun, 9 Apr 2006 08:00:57 +0200 User-Agent: KMail/1.9.1 Cc: linux-kernel@vger.kernel.org References: <20060407095132.455784000@sergelap> <20060408202840.GB26403@sergelap.austin.ibm.com> In-Reply-To: <20060408202840.GB26403@sergelap.austin.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200604090800.57814.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 08 April 2006 22:28, Serge E. Hallyn wrote: > This is something we've been discussing - whether to use a single > "container" structure pointing to all the namespaces, or put everything > into the task_struct. Using container structs means more cache misses > and refcounting issues, but keeps task_struct smaller as you point out. The more cache misses argument seems bogus to me. If you consider the case of a lot of processes with lots of shared name spaces the overall foot print should be in fact considerable less. > The consensus so far has been to start putting things into task_struct > and move if needed. At least the performance numbers show that so far > there is no impact. Performance is not the only consider consideration here. Overall memory consumption is important too. Sure for a single namespace like utsname it won't make much difference, but it likely will if you have 10-20 of these things. > > iirc container patches have been sent before. Should those be resent, > then, and perhaps this patchset rebased on those? I think so. -Andi