From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264206AbTEGTHH (ORCPT ); Wed, 7 May 2003 15:07:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264208AbTEGTHH (ORCPT ); Wed, 7 May 2003 15:07:07 -0400 Received: from chaos.analogic.com ([204.178.40.224]:6019 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id S264206AbTEGTHE (ORCPT ); Wed, 7 May 2003 15:07:04 -0400 Date: Wed, 7 May 2003 15:22:23 -0400 (EDT) From: "Richard B. Johnson" X-X-Sender: root@chaos Reply-To: root@chaos.analogic.com To: Davide Libenzi cc: Linux kernel Subject: Re: top stack (l)users for 2.5.69 In-Reply-To: Message-ID: References: <20030507132024.GB18177@wohnheim.fh-wedel.de> <20030507135657.GC18177@wohnheim.fh-wedel.de> <52k7d2pqwm.fsf@topspin.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 7 May 2003, Davide Libenzi wrote: > On Wed, 7 May 2003, Richard B. Johnson wrote: > > > No, No. That is a process stack. Every process has it's own, entirely > > seperate stack. This stack is used only in user mode. The kernel has > > it's own stack. Every time you switch to kernel mode either by > > calling the kernel or by a hardware interrupt, the kernel's stack > > is used. > > Is it your understanding that does not exist a per task kernel stack ? > It is my understanding that there is one kernel stack. If there is a stack allocated for some "transition", and I guess there may be, because of the mail I'm getting, then it has absolutely no purpose whatsoever and is wasted valuable non-paged RAM. The reason why system-call parameters are passed in registers is so that we didn't have the overhead of copying stuff from a user stack to a kernel stack. Does anybody know (not guess) if this was stuff added for the new non-interrupt 0x80 syscall code? I want to know how a simple kernel got corrupted into this twisted thing. Anybody who has a copy of any of the Intel manuals since '386 knows that there needs to be only one kernel stack. Cheers, Dick Johnson Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips). Why is the government concerned about the lunatic fringe? Think about it.