I have been experimenting with setting the nice value of the runaway usb process, and it seems to have good effects. There are basically 4 processes involved in cups printing with this processor: cupsd, gs-esp, rastertogutenprint, and usb. It is the usb process which hogs the cpu. If I set the nice value of the usb process to 10 (using the command renice +10 -p<process id of usb process> then the usb process gets less cpu than rastertogutenprint, and everything goes much faster (on my print server, which is admittedly old and slow, about an order of magnitude faster). Not perfect, but I can print a file in an hour or so which was taking over a day without the renicing.
So, whatever the usb process is doing when it's hogging the cpu, it apparently doesn't need to do nearly so much of it. Graham -- usb backend hogs cpu https://launchpad.net/bugs/55656 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
