From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 2 May 2001 15:35:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 2 May 2001 15:34:55 -0400 Received: from neon-gw.transmeta.com ([209.10.217.66]:13572 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Wed, 2 May 2001 15:34:47 -0400 To: linux-kernel@vger.kernel.org From: torvalds@transmeta.com (Linus Torvalds) Subject: Re: X15 alpha release: as fast as TUX but in user space (fwd) Date: 2 May 2001 12:34:11 -0700 Organization: A poorly-installed InterNetNews site Message-ID: <9cpnfj$ms3$1@penguin.transmeta.com> In-Reply-To: <200104292116.f3TLGhu07016@pachyderm.pa.dec.com> <20010502211800.X805@mea-ext.zmailer.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In article <20010502211800.X805@mea-ext.zmailer.org>, Matti Aarnio wrote: >On Sun, Apr 29, 2001 at 02:16:43PM -0700, Jim Gettys wrote: >... >> "X is an exercise in avoiding system calls". I think I said this around >> 1984-1985. >> - Jim > >I think that applies to all really high-performance servers. Note that it is definitely not always true. Linux system calls are reasonably light-weight. And sometimes trying to avoid them ends up beaing _more_ work - because you might have to worry about synchronization and cache coherency in user mode. So the rule should be "avoid _unnecessary_ system calls". Linus