%         Registration              The usbmon: USB monitoring framework      
%  [2]Register/Submit Proposal Pete Zaitcev (zaitcev@redhat.com)              

For years, Linux developers used \ident{printk()} to   
debug the USB stack, but this approach has     
serious limitations. In this paper we discuss  
``usbmon,'' a recently developed facility to     
snoop USB traffic in a more efficient way than 
can be done with \ident{printk()}.                     

From far away, usbmon is a very                
straightforward piece of code. It consists of  
circular buffers which are filled with records 
by hooks into the USB stack, and a thin glue   
to the user code which fetches these records.  
The devil, however, is in details. Also the    
user mode tools play a role.