From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 4 Jan 2001 07:34:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 4 Jan 2001 07:33:59 -0500 Received: from linuxcare.com.au ([203.29.91.49]:56580 "EHLO front.linuxcare.com.au") by vger.kernel.org with ESMTP id ; Thu, 4 Jan 2001 07:33:43 -0500 From: Anton Blanchard Date: Thu, 4 Jan 2001 23:32:11 +1100 To: Andi Kleen Cc: Daniel Phillips , ludovic fernandez , linux-kernel@vger.kernel.org Subject: Re: [PATCH] 2.4.0-prerelease: preemptive kernel. Message-ID: <20010104233211.A20942@linuxcare.com> In-Reply-To: <3A53D863.53203DF4@sun.com> <3A5427A6.26F25A8A@innominate.de> <20010104091118.A18973@gruyere.muc.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.12i In-Reply-To: <20010104091118.A18973@gruyere.muc.suse.de>; from ak@suse.de on Thu, Jan 04, 2001 at 09:11:18AM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > I think a better way to proceed would be to make semaphores a bit more > intelligent and turn them into something like adaptive spinlocks and use > them more where appropiate (currently using semaphores usually causes > lots of context switches where some could probably be avoided). Problem > is that for some cases like your producer-consumer pattern (which has been > used previously in unreleased kernel code BTW) it would be a pessimization > to spin, so such adaptive locks would probably need a different name. Like solaris adaptive mutexes? It would be interesting to test, however considering read/write semaphores are hardly ever used these days we want to be sure they are worth it before adding yet another synchronisation primitive. Anton - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/