From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261735AbVHBTd3 (ORCPT ); Tue, 2 Aug 2005 15:33:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261746AbVHBTd3 (ORCPT ); Tue, 2 Aug 2005 15:33:29 -0400 Received: from dgate1.fujitsu-siemens.com ([217.115.66.35]:60775 "EHLO dgate1.fujitsu-siemens.com") by vger.kernel.org with ESMTP id S261735AbVHBTd2 (ORCPT ); Tue, 2 Aug 2005 15:33:28 -0400 X-SBRSScore: None X-IronPort-AV: i="3.95,162,1120428000"; d="scan'208"; a="13504288:sNHT29822596" Message-ID: <42EFCA87.6090109@fujitsu-siemens.com> Date: Tue, 02 Aug 2005 21:33:27 +0200 From: Bodo Stroesser User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.3) Gecko/20040913 X-Accept-Language: en-us, en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: lpfc: system freezing if FC connection is broken under load 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 Hi, my dual Xeon machine freezes, if connection between FC switch and tape drives is broken while writing to tapes. There is one SCSI target with 16 tape LUNs connected to my FC controller via FC switch. I can reproduce the problem by starting "dd if=/dev/zero of=/dev/st[0-7] bs=256K" on the first 8 LUNs. Then I unplug the connection between switch and tapes. It doesn't matter if using LP9802 or one channel of LP9402DC. The problem happens immediately after cfg_nodev_tmo has run out. If nodev_tmo is changed, time from breaking connection to machine freezing changes accordingly. After the problem happened, even NMIs no longer are handled. I added nmi_watchdog=1 to cmdline and added some simple code to nmi handler, that writes the nmi counter directly to video ram. In case of error, nmi no longer counts (but I have no idea, how this can happen, maybe there is some HW bug). What could I do to analyze the problem? Please CC me, I'm not on the list. Regards Bodo