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-rw-r--r--kernel/trace/Kconfig13
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index ce70677..1399f37 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -8,3 +8,16 @@ config TRACING
bool
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.
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