GIANT_LOCK in release7.0

[Kris Kennaway]

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