From owner-freebsd-current@FreeBSD.ORG  Wed Nov 10 21:58:14 2004
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 3B6A716A4CE; Wed, 10 Nov 2004 21:58:14 +0000 (GMT)
Received: from mail.vicor-nb.com (bigwoop.vicor-nb.com [208.206.78.2])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id C4EDF43D2F; Wed, 10 Nov 2004 21:58:11 +0000 (GMT)
	(envelope-from julian@elischer.org)
Received: from elischer.org (julian.vicor-nb.com [208.206.78.97])
	by mail.vicor-nb.com (Postfix) with ESMTP
	id 5A2057A423; Wed, 10 Nov 2004 13:58:09 -0800 (PST)
Message-ID: <41928EF0.6070205@elischer.org>
Date: Wed, 10 Nov 2004 13:58:08 -0800
From: Julian Elischer <julian@elischer.org>
User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.3.1) Gecko/20030516
X-Accept-Language: en, hu
MIME-Version: 1.0
To: Robert Watson <rwatson@freebsd.org>
References: <Pine.NEB.3.96L.1041110204022.60848D-100000@fledge.watson.org>
In-Reply-To: <Pine.NEB.3.96L.1041110204022.60848D-100000@fledge.watson.org>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
cc: current@freebsd.org
Subject: Re: Some problems with KDB/scheduler?
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 10 Nov 2004 21:58:14 -0000



Robert Watson wrote:

>I've been having some problems with KDB this evening; right now what I'm
>bumping into appears to be a problem with interrupts and KDB/DDB.  An
>example below.
>
>(debugger entered using sysctl debug.kdb.enter=1)
>
>db
>tiger-3# [thread 100071]
>Breakpoint at   vlan_start:     pushl   %ebp
>db> cont
>KDB: stack backtrace:
>mi_switch(6,c5457300,c5457450,c5457300,e7868c48) at mi_switch+0x2ce
>maybe_preempt(c5457300,e7868c40,c06033ce,197,c080c288) at
>maybe_preempt+0xf9
>sched_add(c5457300) at sched_add+0x26a
>


ithread_schedule() doesn't call sched_add().. It calls setrunqueue() 
which calls
sched_add().

this looks like something that was reported a few days ago where
it looks like kdb/ddb is skipping frames.

>ithread_schedule(c5455500,c5404a80,12,0,c554da00) at ithread_schedule+0x8a
>intr_execute_handlers(c53fc5e0,e7868ca8,12,e7868cec,c0793e03) at
>intr_execute_ha
>ndlers+0x65
>lapic_handle_intr(42) at lapic_handle_intr+0x23
>Xapic_isr2() at Xapic_isr2+0x33
>--- interrupt, eip = 0xc0a27b71, esp = 0xe7868cec, ebp = 0xe7868cec ---
>acpi_cpu_c1(e7868d04,c0619321,c08d1520,1,fffffffe) at acpi_cpu_c1+0x5
>acpi_cpu_idle(c05f8328,c5403600,e7868d34,c05f811e,0) at acpi_cpu_idle+0xe1
>idle_proc(0,e7868d48,0,c05f8328,0) at idle_proc+0x65
>fork_exit(c05f8328,0,e7868d48) at fork_exit+0x7e
>fork_trampoline() at fork_trampoline+0x8
>--- trap 0x1, eip = 0, esp = 0xe7868d7c, ebp = 0 ---
>panic: mi_switch: did not reenter debugger
>cpuid = 0
>boot() called on cpu#0
>Uptime: 1m26s
>
>_______________________________________________
>
>  
>