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| author | Steven Rostedt <srostedt@redhat.com> | 2008-11-05 21:05:44 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-06 06:50:51 (GMT) |
| commit | 60a7ecf42661f2b22168751298592da6ee210c9e (patch) | |
| tree | 050fd052c546c92f8aac10ee71d5bb6d98a21fc8 /kernel/trace/Kconfig | |
| parent | 79c81d220c8e25163f56edcdfaf23f83a4c88e6b (diff) | |
| download | linux-fsl-qoriq-60a7ecf42661f2b22168751298592da6ee210c9e.tar.xz | |
ftrace: add quick function trace stop
Impact: quick start and stop of function tracer
This patch adds a way to disable the function tracer quickly without
the need to run kstop_machine. It adds a new variable called
function_trace_stop which will stop the calls to functions from mcount
when set. This is just an on/off switch and does not handle recursion
like preempt_disable().
It's main purpose is to help other tracers/debuggers start and stop tracing
fuctions without the need to call kstop_machine.
The config option HAVE_FUNCTION_TRACE_MCOUNT_TEST is added for archs
that implement the testing of the function_trace_stop in the mcount
arch dependent code. Otherwise, the test is done in the C code.
x86 is the only arch at the moment that supports this.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/Kconfig')
| -rw-r--r-- | kernel/trace/Kconfig | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 33dbefd..fc4febc 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -9,6 +9,13 @@ config NOP_TRACER config HAVE_FUNCTION_TRACER bool +config HAVE_FUNCTION_TRACE_MCOUNT_TEST + bool + help + This gets selected when the arch tests the function_trace_stop + variable at the mcount call site. Otherwise, this variable + is tested by the called function. + config HAVE_DYNAMIC_FTRACE bool |