x86, bts, ftrace: a BTS ftrace plug-in prototype
Impact: add new ftrace plugin
A prototype for a BTS ftrace plug-in.
The tracer collects branch trace in a cyclic buffer for each cpu.
The tracer is not configurable and the trace for each snapshot is
appended when doing cat /debug/tracing/trace.
This is a proof of concept that will be extended with future patches
to become a (hopefully) useful tool.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 9cbf776..620fead 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -28,6 +28,9 @@
config HAVE_FTRACE_MCOUNT_RECORD
bool
+config HAVE_HW_BRANCH_TRACER
+ bool
+
config TRACER_MAX_TRACE
bool
@@ -233,6 +236,14 @@
Say N if unsure.
+config BTS_TRACER
+ depends on HAVE_HW_BRANCH_TRACER
+ bool "Trace branches"
+ select TRACING
+ help
+ This tracer records all branches on the system in a circular
+ buffer giving access to the last N branches for each cpu.
+
config DYNAMIC_FTRACE
bool "enable/disable ftrace tracepoints dynamically"
depends on FUNCTION_TRACER