From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932484AbWFHCbF (ORCPT ); Wed, 7 Jun 2006 22:31:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932490AbWFHCbF (ORCPT ); Wed, 7 Jun 2006 22:31:05 -0400 Received: from tomts20.bellnexxia.net ([209.226.175.74]:18656 "EHLO tomts20-srv.bellnexxia.net") by vger.kernel.org with ESMTP id S932484AbWFHCbE (ORCPT ); Wed, 7 Jun 2006 22:31:04 -0400 Date: Wed, 7 Jun 2006 22:31:02 -0400 From: Mathieu Desnoyers To: Jon Smirl Cc: linux-kernel@vger.kernel.org, ltt-dev@shafik.org Subject: Re: Interrupts disabled for too long in printk Message-ID: <20060608023102.GA22022@Krystal> References: <20060603111934.GA14581@Krystal> <9e4733910606071837l4e81c975t8d531ed9810af60f@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <9e4733910606071837l4e81c975t8d531ed9810af60f@mail.gmail.com> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.4.31-grsec (i686) X-Uptime: 22:28:27 up 33 days, 5:37, 1 user, load average: 1.16, 1.26, 1.24 User-Agent: Mutt/1.5.11+cvs20060403 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Jon Smirl (jonsmirl@gmail.com) wrote: > You can look at this problem from the other direction too. Why is it > taking 15ms to get between the two points? If IRQs are off how is the > serial driver getting interrupts to be able to display the message? It > is probably worthwhile to take a look and see what the serial console > driver is doing. Hi John, The serial port is configured at 38000 bauds. It can therefore transmit 4800 bytes per seconds, for 72 characters in 15 ms. So the console driver would be simply busy sending characters to the serial port during that interrupt disabling period. Mathieu OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68