Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262728AbUKTLvu (ORCPT ); Sat, 20 Nov 2004 06:51:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262735AbUKTLvu (ORCPT ); Sat, 20 Nov 2004 06:51:50 -0500 Received: from imap.gmx.net ([213.165.64.20]:36321 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S262728AbUKTLuR (ORCPT ); Sat, 20 Nov 2004 06:50:17 -0500 X-Authenticated: #4399952 Date: Sat, 20 Nov 2004 12:50:57 +0100 From: Florian Schmidt To: Lee Revell Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Rui Nuno Capela , Mark_H_Johnson@Raytheon.com, "K.R. Foley" , Bill Huey , Adam Heath , Thomas Gleixner , Michal Schmidt , Fernando Pablo Lopez-Lezcano , Karsten Wiese , Gunther Persoons , emann@mrv.com, Shane Shrybman , Amit Shah Subject: Re: [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.29-0 Message-ID: <20041120125057.03b3d8c4@mango.fruits.de> In-Reply-To: <1100920963.1424.1.camel@krustophenia.net> References: <20041108091619.GA9897@elte.hu> <20041108165718.GA7741@elte.hu> <20041109160544.GA28242@elte.hu> <20041111144414.GA8881@elte.hu> <20041111215122.GA5885@elte.hu> <20041116125402.GA9258@elte.hu> <20041116130946.GA11053@elte.hu> <20041116134027.GA13360@elte.hu> <20041117124234.GA25956@elte.hu> <20041118123521.GA29091@elte.hu> <20041118164612.GA17040@elte.hu> <1100920963.1424.1.camel@krustophenia.net> X-Mailer: Sylpheed-Claws 0.9.12b (GTK+ 1.2.10; i386-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1253 Lines: 39 On Fri, 19 Nov 2004 22:22:42 -0500 Lee Revell wrote: > On Thu, 2004-11-18 at 17:46 +0100, Ingo Molnar wrote: > > i have released the -V0.7.29-0 Real-Time Preemption patch, which can be > > downloaded from the usual place: > > > > http://redhat.com/~mingo/realtime-preempt/ > > I tried this with CONFIG_PREEMPT_VOLUNTARY (which should theoretically > work like the earlier VP patches, right?) to test for regressions. The > boot process hung after initializing my IDE controller. I thought so, too, until ingo set me straight (quote ingo): here are the different layers of preemption: - !PREEMPT - PREEMPT_VOLUNTARY - PREEMPT - PREEMPT_RT each step forward decreases latencies, at the cost of more runtime overhead. so PREEMPT_VOLUNTARY is not "the" feature anymore, it's "a" feature down the hierarchy. In fact the focus is mostly on PREEMPT_RT now. quote end.. So with RP kernels, PREEMPT is what gives best latency when full realtime preemption is not an option flo - 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/