From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264150AbTEGSVX (ORCPT ); Wed, 7 May 2003 14:21:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264152AbTEGSVX (ORCPT ); Wed, 7 May 2003 14:21:23 -0400 Received: from x35.xmailserver.org ([208.129.208.51]:21417 "EHLO x35.xmailserver.org") by vger.kernel.org with ESMTP id S264150AbTEGSVW convert rfc822-to-8bit (ORCPT ); Wed, 7 May 2003 14:21:22 -0400 X-AuthUser: davidel@xmailserver.org Date: Wed, 7 May 2003 11:35:25 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@blue1.dev.mcafeelabs.com To: =?iso-8859-1?Q?J=F6rn?= Engel cc: Linux kernel Subject: Re: top stack (l)users for 2.5.69 In-Reply-To: <20030507174027.GD19324@wohnheim.fh-wedel.de> Message-ID: References: <20030507132024.GB18177@wohnheim.fh-wedel.de> <20030507135657.GC18177@wohnheim.fh-wedel.de> <20030507143315.GA6879@stargate.galaxy> <20030507144736.GE8978@holomorphy.com> <20030507164901.GB19324@wohnheim.fh-wedel.de> <20030507174027.GD19324@wohnheim.fh-wedel.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=X-UNKNOWN Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 7 May 2003, [iso-8859-1] Jörn Engel wrote: > I'm not sure if I got you wrong, or vice versa. Either way, some > definitions first. > Process Stack == the traditional per-process kernel stack > Interrupt Stack == a dedicated per-CPU stack for interrupts only > CPU Stack == all kernel data on a per-CPU stack > > Not for anything would I want a CPU Stack. At first thought, this is > impossible, but in reality it is just ugly beyond anything I could > bear. > > An Interrupt Stack is a very good thing. I know PPC machines with 125 > Interrupt lines (3 for cascading) that could theoretically all happen > at once. That alone demands for a stack size well above 8k and having > this per process is just a bad design. But that is another issue. > > The real Process Stack without the interrupt overhead should not need > to be bigger than 4k. It currently is for all platforms I know about, > s390 has even 16k. This is the point of my regular allyesconfig > compilations and postings. > > Do you still disagree? Then I must have misread your mail. It was not really clear you were talking about interrupts stack, that are a feasible thing. Even though, I'd not feel confident going down to 4k, looking at the post that started this thread. - Davide