From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965024AbXASJf1 (ORCPT ); Fri, 19 Jan 2007 04:35:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965023AbXASJf1 (ORCPT ); Fri, 19 Jan 2007 04:35:27 -0500 Received: from gateway1.seskion.de ([62.8.128.82]:21446 "EHLO gateway1.seskion.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965003AbXASJf0 (ORCPT ); Fri, 19 Jan 2007 04:35:26 -0500 Message-ID: <45B090D9.7020602@seskion.de> Date: Fri, 19 Jan 2007 10:35:21 +0100 From: Juergen Pfeiffer Organization: SesKion Softwareentwicklung und System Konzeption GmbH User-Agent: Thunderbird 1.5.0.9 (Windows/20061207) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Re: long disable of Softirqs in br_forward_delay_timer_expired() References: <45AF79AE.1060102@seskion.de> In-Reply-To: <45AF79AE.1060102@seskion.de> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Juergen Pfeiffer schrieb: > > I had problems in my implementation of Profibus-protocol, because my > FDL-State machine is implemented in tasklets and > sometimes there were situations, where Soft-Irqs were disabled for > 20-40mS (Coldfire 5485 / 96MHz). > After inserting some testpoints in kernels source, doing dump_stack(), > when the jiffie-time get longer then 20mS, > i detected the place of the long Soft-Irq disable in function > > static void br_forward_delay_timer_expired(..) > inside file "net/bridge/br_stp_timer.c" > > It does a > spin_lock_bh(..); > ... some functionality; > spin_unlock_bh(..); Hi I found the reason for the long disabling of Soft-Irqs: In-between the spin_lock_bh() and spin_unlock_bh() was a printk() going to serial console with 19200baud. So it took easily 30mS for console-output. No i start klogd an the log Messages go to a file in tmpfs in a short time. Juergen Pfeiffer, Seskion GmbH Karlsruher Str. 11/1 70771 Leinfelden-Echterdingen Germany j.pfeiffer@seskion.de www.seskion.de ------------------------------------------------------------------------