From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261909AbULKCWz (ORCPT ); Fri, 10 Dec 2004 21:22:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261910AbULKCWy (ORCPT ); Fri, 10 Dec 2004 21:22:54 -0500 Received: from gateway-1237.mvista.com ([12.44.186.158]:5873 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S261909AbULKCWw (ORCPT ); Fri, 10 Dec 2004 21:22:52 -0500 Message-ID: <41BA59F6.5010309@mvista.com> Date: Fri, 10 Dec 2004 18:22:46 -0800 From: George Anzinger Reply-To: george@mvista.com Organization: MontaVista Software User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.2) Gecko/20040308 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Zwane Mwaikambo CC: Lee Revell , dipankar@in.ibm.com, ganzinger@mvista.com, Manfred Spraul , lkml Subject: Re: RCU question References: <41B8E6F1.4070007@mvista.com> <20041210043102.GC4161@in.ibm.com> <41B9FC3F.50601@mvista.com> <20041210204003.GC4073@in.ibm.com> <1102711532.29919.35.camel@krustophenia.net> <41BA0ECF.1060203@mvista.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Zwane Mwaikambo wrote: > On Fri, 10 Dec 2004, George Anzinger wrote: > > >>>Well, softirqs should really be preemptible if you care about RT task >>>latency. Ingo's patches have had this for months. Works great. Maybe >>>it's time to push it upstream. >> >>Yes, I understand, and soft_irq() does turn on interrupts... >>I was thinking of something like: >> >> while(softirq_pending()) { >> local_irq_enable(); >> do_softirq(); >> local_irq_disable(); >> } >> > > > But that's a deadlock and if you enable interrupts you race. Again, I remind you we are in the idle task. Nothing more important to do. Or do you mean that softirq_pending() will NEVER return false? The other question is: "Is useful work being done?" -- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/