1

I was going through a Linux KERNEL configuration file wherein function_trace is enabled but debugfs is disabled. If i load this kernel onto the target is there any way, I can make use of the function_tracer ? if debugfs is disabled is it that the function tracer is not enabled by default ?

Ciro Santilli OurBigBook.com
  • 347,512
  • 102
  • 1,199
  • 985
lxusr
  • 987
  • 3
  • 16
  • 28

1 Answers1

1

Technically it's not possible to select function_trace without debugfs enabled. As per tracing configuration file (https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/kernel/trace/Kconfig#n140), it suggest that - if you select FUNCTION_TRACER, it'll automatically select GENERIC_TRACER and when GENERIC_TRACER is selected this will automatically select TRACING (https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/kernel/trace/Kconfig#n112) and when TRACING is selected it'll select DEBUG_FS (https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/kernel/trace/Kconfig#n101).

So, it's a linked list of selection procedure and you do not need to select each option every time. Until unless you've modified config file by hand and it's not recommended.

rakib_
  • 136,911
  • 4
  • 20
  • 26