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 16:52:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 2 May 2001 16:52:01 -0400 Received: from chromium11.wia.com ([207.66.214.139]:42763 "EHLO neptune.kirkland.local") by vger.kernel.org with ESMTP id ; Wed, 2 May 2001 16:51:55 -0400 Message-ID: <3AF07459.8D8ECD8E@chromium.com> Date: Wed, 02 May 2001 13:55:53 -0700 From: Fabio Riccardi X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.2 i686) X-Accept-Language: en MIME-Version: 1.0 CC: linux-kernel@vger.kernel.org Subject: Re: X15 alpha release: as fast as TUX but in user space (fwd) In-Reply-To: <200104292116.f3TLGhu07016@pachyderm.pa.dec.com> <20010502211800.X805@mea-ext.zmailer.org> <9cpnfj$ms3$1@penguin.transmeta.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: unlisted-recipients:; (no To-header on input)@localhost.localdomain Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>From my experience system calls are not an issue. What costs a lot is moving data around, since modern CPUs spend most of their time in memory/bus wait cycles... - Fabio Linus Torvalds wrote: > >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 > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/