From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262768AbTJPIYS (ORCPT ); Thu, 16 Oct 2003 04:24:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262777AbTJPIYS (ORCPT ); Thu, 16 Oct 2003 04:24:18 -0400 Received: from ltgp.iram.es ([150.214.224.138]:12417 "EHLO ltgp.iram.es") by vger.kernel.org with ESMTP id S262768AbTJPIYR (ORCPT ); Thu, 16 Oct 2003 04:24:17 -0400 From: Gabriel Paubert Date: Thu, 16 Oct 2003 10:16:11 +0200 To: linux-kernel@vger.kernel.org Subject: Re: Unbloating the kernel, action list Message-ID: <20031016081611.GA14949@iram.es> References: <20031014214311.GC933@inwind.it> <16710000.1066170641@flay> <20031014155638.7db76874.cliffw@osdl.org> <20031015124842.GE20846@lug-owl.de> <20031015131015.GR16158@holomorphy.com> <20031015181658.GA9652@iram.es> <20031016051951.GP20846@lug-owl.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031016051951.GP20846@lug-owl.de> User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 16, 2003 at 07:19:51AM +0200, Jan-Benedict Glaw wrote: > On Wed, 2003-10-15 20:16:58 +0200, Gabriel Paubert > wrote in message <20031015181658.GA9652@iram.es>: > > On Wed, Oct 15, 2003 at 06:10:15AM -0700, William Lee Irwin III wrote: > > > On Tue, 2003-10-14 15:56:38 -0700, cliff white > > > Can you quantify the performance impact of cmov emulation (or whatever > > > it is)? I have a vague notion it could be hard given the daunting task > > > of switching userspace around to verify it. > > The other problem of the 386 is that it has a fundamental MMU flaw: > > no write protection on kernel mode accesses to user space, which makes > > put_user() intrinsically racy on a 386 and way more bloated when it is > > inlined (access_ok has to call a function which searches the VMA tree). > > However, this problem exists since the very first hour. Linux once > really ran quite well on those machines... Yes, but VM sharing between threads was rather infrequent back then and you need shared VM to create the race. > > I've rebooted my P-Classic router last night. Maybe I can see (in two > weeks or in a month or the like...) why it slows down, even with 32MB > RAM... It might be related to the size-4096 memory leak others are reporting right now. I don't know, but it's not such a far-fetched hypothesis either. Gabriel