From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261896AbUKHRP5 (ORCPT ); Mon, 8 Nov 2004 12:15:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261946AbUKHROr (ORCPT ); Mon, 8 Nov 2004 12:14:47 -0500 Received: from alog0232.analogic.com ([208.224.220.247]:3456 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id S261896AbUKHQvZ (ORCPT ); Mon, 8 Nov 2004 11:51:25 -0500 Date: Mon, 8 Nov 2004 11:50:20 -0500 (EST) From: linux-os Reply-To: linux-os@analogic.com To: Linux kernel Subject: More linux-2.6.9 module problems Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I have a memory-test procedure that tests memory on a board, accessed via the PCI bus. There is a lot of RAM and it's bank-switched into some 64k windows so it takes a lot of time to test, about 60 seconds. This is in a module, therefore inside the kernel. When it is invoked via an ioctl() call, the kernel is frozen for the whole test-time. The test procedure does not use any spin-locks nor does it even use any semaphores. It just does a bunch of read/write operations over the PCI/Bus. I thought that I could enable the preemptible- kernel option and the machine would then respond normally. Not so. Even with 4 CPUs, when one ioctl() is busy in the kernel, nothing else happens until its done. Even keyboard activity is gone, no Caps Lock and no Num Lock, no `ping` response over the network. However, the machine comes back to life when the memory-test is done. This is kernel version 2.6.9. Is it possible that somebody left on the BKL when calling a module ioctl() on this version? If not, what do I do to be able to execute a time-consuming procedure from inside the kernel? Do I break it up into sections and execute schedule() periodically (temporary work-around --works)?? Cheers, Dick Johnson Penguin : Linux version 2.6.9 on an i686 machine (5537.79 BogoMips). Notice : All mail here is now cached for review by John Ashcroft. 98.36% of all statistics are fiction.