|  | Poor-man's Ftrace is a live printk function tracer.  It does not handle | 
|  | concurrency well, whether that is interleaved IRQs or especially parallelism. | 
|  | Everything gets printed at the same time, and shares the same global | 
|  | indentation variable.  Still, it works reasonably well for IRQs, ktasks, and | 
|  | syscalls. | 
|  |  | 
|  | Careful using this on certain devices in k/d/dev/, like acpi and console.  One | 
|  | of the devs locks up if you try to print. | 
|  |  | 
|  | I usually turn off the 'print' bool in kdebug.c for booting, then turn it on | 
|  | via 'kfunc toggle_print_func'. | 
|  |  | 
|  | To spatch the networking code, try something like: | 
|  |  | 
|  | $ for i in kern/src/net kern/drivers/net kern/drivers/dev/ether.c; do | 
|  | spatch --sp-file scripts/spatch/poor-ftrace.cocci  --in-place $i; done |