From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 28 May 2001 15:18:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 28 May 2001 15:18:46 -0400 Received: from femail9.sdc1.sfba.home.com ([24.0.95.89]:11956 "EHLO femail9.sdc1.sfba.home.com") by vger.kernel.org with ESMTP id ; Mon, 28 May 2001 15:18:35 -0400 From: "Arthur Naseef" To: Subject: Kernel 2.2: tq_scheduler functions scheduling and waiting Date: Mon, 28 May 2001 15:19:17 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Importance: Normal Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org All: I have been diagnosing kernel panics for over a week and I have concerns with the use of tq_scheduler for which I was hoping I could get some assistance. Is it considered acceptable for functions in the tq_scheduler task list to call schedule? Is it acceptable for such functions to wait on wait queues? What limitations exist? As near as I can determine, the TTY driver code makes use of the tq_scheduler list for such purposes. In my testing, I am running with 96 TTY devices (talking to a high-density modem card) and I consistently achieve kernel panics when the system is under heavy swapping. I am continuing to diagnose the problem. The kernel panics are triggered mostly in goodness() and del_from_runqueue(), as indicated by ksym_oops and gdb, and I suspect the run queue is getting corrupted. In spite of this testing, I believe that I have an argument against tq_scheduler functions waiting on wait queues, but I have not thoroughly convinced myself that (a) this was not already known, and (b) this is already happening in existing kernel code. Any help is greatly appreciated. -art Arthur Naseef P.S. If this information is availed through existing documentation, searches, or other widely available resources, I would greatly appreciate references to this material. All of my searches to date have yielded few results and nothing definitive.