#
# Architectures that offer an FTRACE implementation should select HAVE_FTRACE:
config HAVE_FTRACE
bool
config TRACING
select DEBUG_FS
config FTRACE
bool "Kernel Function Tracer"
depends on DEBUG_KERNEL && HAVE_FTRACE
select FRAME_POINTER
select TRACING
help
Enable the kernel to trace every kernel function. This is done
by using a compiler feature to insert a small, 5-byte No-Operation
instruction to the beginning of every kernel function, which NOP
sequence is then dynamically patched into a tracer call when
tracing is enabled by the administrator. If it's runtime disabled
(the bootup default), then the overhead of the instructions is very
small and not measurable even in micro-benchmarks.
