From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261936AbVFLKgK (ORCPT ); Sun, 12 Jun 2005 06:36:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261942AbVFLKgJ (ORCPT ); Sun, 12 Jun 2005 06:36:09 -0400 Received: from mx2.elte.hu ([157.181.151.9]:54991 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S261936AbVFLKfz (ORCPT ); Sun, 12 Jun 2005 06:35:55 -0400 Date: Sun, 12 Jun 2005 12:35:13 +0200 From: Ingo Molnar To: Gene Heskett Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , "Eugeny S. Mints" , Daniel Walker Subject: Re: [patch] Real-Time Preemption, -RT-2.6.12-rc6-V0.7.48-00 Message-ID: <20050612103513.GA10808@elte.hu> References: <20050608112801.GA31084@elte.hu> <200506112140.36352.gene.heskett@verizon.net> <20050612064939.GB4897@elte.hu> <200506120502.01752.gene.heskett@verizon.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200506120502.01752.gene.heskett@verizon.net> 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 * Gene Heskett wrote: > Glitch reports as they develop of course. > > Q: Whats the diff between turning on hardirq's in mode 3, and mode 4? well, "mode 3" is PREEMPT_DESKTOP - normal CONFIG_PREEMPT on the mainstream kernel. If you turn on hardirq/softirq threading then you can e.g. chprio your sound IRQ to have better audio latencies. It will cause runtime overhead though. On "mode 4" (PREEMPT_RT) hardirq/softirq threading is mandatory (due to the processing model). Ingo