From owner-freebsd-current@FreeBSD.ORG Thu Jun 9 18:38:37 2005 Return-Path: X-Original-To: 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 3755116A41C for ; Thu, 9 Jun 2005 18:38:37 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: from obsecurity.dyndns.org (CPE0050040655c8-CM00111ae02aac.cpe.net.cable.rogers.com [69.194.102.232]) by mx1.FreeBSD.org (Postfix) with ESMTP id CE83443D53 for ; Thu, 9 Jun 2005 18:38:36 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: by obsecurity.dyndns.org (Postfix, from userid 1000) id 2475151288; Thu, 9 Jun 2005 14:38:36 -0400 (EDT) Date: Thu, 9 Jun 2005 14:38:35 -0400 From: Kris Kennaway To: current@FreeBSD.org Message-ID: <20050609183835.GA9451@xor.obsecurity.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="qMm9M+Fa2AknHoGS" Content-Disposition: inline User-Agent: Mutt/1.4.2.1i Cc: Subject: mutex still spinning while in DDB on UP machine X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Jun 2005 18:38:37 -0000 --qMm9M+Fa2AknHoGS Content-Type: text/plain; charset=us-ascii Content-Disposition: inline I've seen the following a couple of times recently on UP machines running up-to-date current (the panic may not be important, I'm referring to the behaviour of DDB): Fatal trap 12: page fault while in kernel mode fault virtual address = 0x0 fault code = supervisor write, page not present instruction pointer = 0x20:0xc054cc77 stack pointer = 0x28:0xd4222c9c frame pointer = 0x28:0xd4222cb4 code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, def32 1, gran 1 processor eflags = interrupt enabled, resume, IOPL = 0 current process = 37 (vnlru) [thread pid 37 tid 100035 ] Stopped at vnlru_free+0x87: movl %eax,0(%edx) db> stray irq7 stray irq7 stray irq7 stray irq7 too many stray irq 7's: not logging anymore At this point, the keyboard only works sporadically (i.e. I have to press keys multiple times for DDB to receive the input). show ktr shows a buffer full of: 530: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 529: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:265 528: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 527: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:265 526: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 525: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:265 524: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 523: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:265 522: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 521: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:265 520: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 519: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:265 518: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:277 517: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:275 516: UNLOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:427 515: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:275 514: UNLOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:427 513: LOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:422 512: UNLOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:427 511: LOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:422 510: UNLOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:427 509: LOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:422 508: UNLOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:427 507: LOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:422 506: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 505: LOCK (spin mutex) clk r = 0 at ../../../i386/isa/clock.c:422 504: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 503: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:265 502: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 501: LOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:265 500: UNLOCK (spin mutex) icu r = 0 at ../../../i386/isa/atpic.c:267 [...] and repeated show ktr indicates that it is still logging events (i.e. the head of the buffer is now in a different place). This suggests that the mutex is still spinning even though the system is in DDB. Kris --qMm9M+Fa2AknHoGS Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (FreeBSD) iD8DBQFCqIyrWry0BWjoQKURAiO2AJ0X0YuPChJg8jjZbgdyk2XVrAx0ngCgohla VpUweC/luOGv6jHLtSYSSlw= =TedK -----END PGP SIGNATURE----- --qMm9M+Fa2AknHoGS--