tracing/fastboot: Document the need of initcall_debug
To use boot tracer, one should pass initcall_debug as well as
ftrace=initcall to the command line.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A48735E.9050002@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 1551f47..019f380 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -226,13 +226,13 @@
the timings of the initcalls and traces key events and the identity
of tasks that can cause boot delays, such as context-switches.
- Its aim is to be parsed by the /scripts/bootgraph.pl tool to
+ Its aim is to be parsed by the scripts/bootgraph.pl tool to
produce pretty graphics about boot inefficiencies, giving a visual
representation of the delays during initcalls - but the raw
/debug/tracing/trace text output is readable too.
- You must pass in ftrace=initcall to the kernel command line
- to enable this on bootup.
+ You must pass in initcall_debug and ftrace=initcall to the kernel
+ command line to enable this on bootup.
config TRACE_BRANCH_PROFILING
bool