From owner-freebsd-questions@FreeBSD.ORG Thu Nov 27 20:58:50 2008 Return-Path: Delivered-To: freebsd-questions@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 22A9C1065674 for ; Thu, 27 Nov 2008 20:58:50 +0000 (UTC) (envelope-from kris@FreeBSD.org) Received: from weak.local (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id CD2248FC0A; Thu, 27 Nov 2008 20:58:49 +0000 (UTC) (envelope-from kris@FreeBSD.org) Message-ID: <492F0A46.2050402@FreeBSD.org> Date: Thu, 27 Nov 2008 12:59:50 -0800 From: Kris Kennaway User-Agent: Thunderbird 2.0.0.18 (Macintosh/20081105) MIME-Version: 1.0 To: akberos@math.berkeley.edu References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-questions@FreeBSD.org, "Alexander K. Beros" Subject: Re: GIANT_LOCK in release7.0 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Nov 2008 20:58:50 -0000 Alexander K. Beros wrote: > > I have not been able to find any discussion of the following issue. Ever > since I upgraded to release 7.0, whenever I print to my network printer (I > am using Samba) I get the following output to ttyv0: > > lpt0: [GIANT-LOCKED] > lpt0: [ITHREAD] > lpt0: [GIANT-LOCKED] > lpt0: [ITHREAD] > lpt0: [GIANT-LOCKED] > lpt0: [ITHREAD] > lpt0: [GIANT-LOCKED] > lpt0: [ITHREAD] > lpt0: [GIANT-LOCKED] > lpt0: [ITHREAD] > > ... this can continue for a very long time depending on the size of the > queue > > The actual printing is fine, and since I am rarely at the terminal it isn't > a serious problem. In fact, if I am working at the server and someone else > is sending jobs to the printer I switch over to ttyv1, so there is really no > inconvenience. > > On the other hand, I thought that release 7 is GIANT_LOCK free, so this is > rather unexpected. I would appreciate any information or explanation. That's not a correct statement. The giant lock is not invoked in most code pathways, but it is still present in some corners of the kernel, for example in some drivers. It's not important for drivers like lpt which are low performance devices. Do you get any additional diagnostics when you boot in verbose mode (boot -v from loader, or use the menu option)? It might be that lpt is encountering an error frequently and resetting itself during I/O. Also please follow up with your entire dmesg. Kris