From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755437AbYDTXwl (ORCPT ); Sun, 20 Apr 2008 19:52:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751518AbYDTXwd (ORCPT ); Sun, 20 Apr 2008 19:52:33 -0400 Received: from bzq-179-150-194.static.bezeqint.net ([212.179.150.194]:12435 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751380AbYDTXwc (ORCPT ); Sun, 20 Apr 2008 19:52:32 -0400 Message-ID: <480BD665.20804@qumranet.com> Date: Mon, 21 Apr 2008 02:48:53 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Bernd Eckenfels CC: linux-kernel@vger.kernel.org Subject: Re: x86: 4kstacks default References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0rc1 (firebolt.argo.co.il [0.0.0.0]); Mon, 21 Apr 2008 02:48:53 +0300 (IDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Bernd Eckenfels wrote: > A question along this line. Why is the Userspace Thread bound to a > Kernel-Space Stack at all? I could imagine a solution like Stack Pools > assigned only of a Thread enters kernel space, or something like this? > > The vast majority of threads are sleeping (with a stack footprint in the kernel). If you have an N-way system, at most N threads can be in userspace at any given moment. You could multiplex several userspace threads on one kernel thread (the M:N model), but it gets fairly complex. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.