From owner-freebsd-current Fri Mar 15 1: 2:11 2002 Delivered-To: freebsd-current@freebsd.org Received: from mail-green.research.att.com (mail-green.research.att.com [135.207.30.103]) by hub.freebsd.org (Postfix) with ESMTP id 7A19137B405; Fri, 15 Mar 2002 01:02:06 -0800 (PST) Received: from alliance.research.att.com (alliance.research.att.com [135.207.26.26]) by mail-green.research.att.com (Postfix) with ESMTP id CE2541E126; Fri, 15 Mar 2002 04:02:05 -0500 (EST) Received: from windsor.research.att.com (windsor.research.att.com [135.207.26.46]) by alliance.research.att.com (8.8.7/8.8.7) with ESMTP id EAA05794; Fri, 15 Mar 2002 04:02:04 -0500 (EST) From: Bill Fenner Received: (from fenner@localhost) by windsor.research.att.com (8.8.8+Sun/8.8.5) id BAA28411; Fri, 15 Mar 2002 01:02:03 -0800 (PST) Message-Id: <200203150902.BAA28411@windsor.research.att.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII To: bde@zeta.org.au Subject: Re: b_to_q to a clist with no reserved cblocks Cc: rwatson@FreeBSD.ORG, current@FreeBSD.ORG Date: Fri, 15 Mar 2002 01:02:03 -0800 Versions: dmail (solaris) 2.4/makemail 2.9b Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG >I don't know exactly what causes the b_to_q message. It is most likely >a race in close. You can first-open tty's that are blocked in last-close, >and having this open succeed is very important for unblocking the close >usi9ng "comcontrol /dev/foo drainwait ", but the tty system doesn't >seem to do nearly enough to handle races here. It happened to me on shutdown, with a serial console. Mar 15 00:58:10 stash reboot: rebooted by fenner panic: b_to_q to a clist with no reserved cblocks. Debugger("panic") Stopped at Debugger+0x40: xorl %eax,%eax db> t Debugger(c03ebb5b) at Debugger+0x40 panic(c03f18c0) at panic+0x70 b_to_q(c7f9bb14,35,c1361a38,0,c7f9bcc8) at b_to_q+0x35 ttwrite(c1361a00,c7f9bcc8,20011,c04b5e80,c7f9bbb4) at ttwrite+0x34c siowrite(c04b5e80,c7f9bcc8,20011,c04b5e80,c7f9bb80) at siowrite+0x78 cnwrite(c04b63d0,c7f9bcc8,20011,c04b63d0,35) at cnwrite+0x74 spec_write(c7f9bc20,c7f9bc34,c02b0c23,c7f9bc20,35) at spec_write+0x5d spec_vnoperate(c7f9bc20,35,c7615500,0,11) at spec_vnoperate+0x15 vn_write(c1392b40,c7f9bcc8,c0a8c980,0,c7615500) at vn_write+0x19f writev(c7615500,c7f9bd20,8054000,bfbfef64,bfbfef34) at writev+0x19a syscall(2f,2f,bfbf002f,bfbfef34,bfbfef64) at syscall+0x278 syscall_with_err_pushed() at syscall_with_err_pushed+0x1b --- syscall (121, FreeBSD ELF, writev), eip = 0x280aae73, esp = 0xbfbfe960, ebp = 0xbfbfe9cc --- I have a dump, if it'd help. Bill To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message