From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262483AbVF2Hr1 (ORCPT ); Wed, 29 Jun 2005 03:47:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262471AbVF2HpW (ORCPT ); Wed, 29 Jun 2005 03:45:22 -0400 Received: from mx1.elte.hu ([157.181.1.137]:35465 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S262472AbVF2Hnx (ORCPT ); Wed, 29 Jun 2005 03:43:53 -0400 Date: Wed, 29 Jun 2005 09:43:39 +0200 From: Ingo Molnar To: Lee Revell Cc: linux-kernel@vger.kernel.org Subject: Re: PREEMPT_RT & threading IRQ 0 Message-ID: <20050629074339.GA19129@elte.hu> References: <1119287612.6863.1.camel@localhost> <20050621015542.GB1298@us.ibm.com> <42B77B8C.6050109@opersys.com> <20050622011931.GF1324@us.ibm.com> <42B9845B.8030404@opersys.com> <1119460661.491.31.camel@mindpipe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1119460661.491.31.camel@mindpipe> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Lee Revell wrote: > Ingo, what's the status of putting irq 0 back in a thread with > PREEMPT_RT? IIRC this had some adverse (maybe unfixable?) effects so > it was disabled a few months ago. the jury is still out on that one - but right now it seems it's too much complexity for a handful of usecs of latency improvement. Especially with things like high-resolution timer support, the threading IRQ0 doesnt seem to be worth it. Ingo