tracing/stacktrace: improve help text

Improve the help text that is displayed for CONFIG_STACK_TRACER.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 396aea11398eaf20ffc8c9ce3b67b9fb9a1ce4ec..11fd03a429f0bcab144b93ae975e7bbf7c3464d0 100644 (file)
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -141,8 +141,17 @@ config STACK_TRACER
        select FTRACE
        select STACKTRACE
        help
-         This tracer records the max stack of the kernel, and displays
-         it in debugfs/tracing/stack_trace
+         This special tracer records the maximum stack footprint of the
+         kernel and displays it in debugfs/tracing/stack_trace.
+
+         This tracer works by hooking into every function call that the
+         kernel executes, and keeping a maximum stack depth value and
+         stack-trace saved. Because this logic has to execute in every
+         kernel function, all the time, this option can slow down the
+         kernel measurably and is generally intended for kernel
+         developers only.
+
+         Say N if unsure.
 
 config DYNAMIC_FTRACE
        bool "enable/disable ftrace tracepoints dynamically"