path: root/include/linux/ftrace.h
diff options
authorFrederic Weisbecker <fweisbec@gmail.com>2008-10-31 12:57:20 +0100
committerIngo Molnar <mingo@elte.hu>2008-11-04 17:14:02 +0100
commit71566a0d161edec70361b7f90f6e54af6a6d5d05 (patch)
tree78d2d790ed4e20c179d2f61f2ed50ecbb6d5a451 /include/linux/ftrace.h
parentMerge branches 'tracing/ftrace', 'tracing/markers', 'tracing/mmiotrace', 'tracing/nmisafe', 'tracing/tracepoints' and 'tracing/urgent' into tracing/core (diff)
tracing/fastboot: Enable boot tracing only during initcalls
Impact: modify boot tracer We used to disable the initcall tracing at a specified time (IE: end of builtin initcalls). But we don't need it anymore. It will be stopped when initcalls are finished. However we want two things: _Start this tracing only after pre-smp initcalls are finished. _Since we are planning to trace sched_switches at the same time, we want to enable them only during the initcall execution. For this purpose, this patch introduce two functions to enable/disable the sched_switch tracing during boot. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/ftrace.h')
1 files changed, 22 insertions, 2 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index e46a7b34037c..4642959e5bda 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -234,6 +234,11 @@ ftrace_init_module(unsigned long *start, unsigned long *end) { }
+ * Structure which defines the trace of an initcall.
+ * You don't have to fill the func field since it is
+ * only used internally by the tracer.
+ */
struct boot_trace {
pid_t caller;
char func[KSYM_NAME_LEN];
@@ -244,13 +249,28 @@ struct boot_trace {
+/* Append the trace on the ring-buffer */
extern void trace_boot(struct boot_trace *it, initcall_t fn);
+/* Tells the tracer that smp_pre_initcall is finished.
+ * So we can start the tracing
+ */
extern void start_boot_trace(void);
-extern void stop_boot_trace(void);
+/* Resume the tracing of other necessary events
+ * such as sched switches
+ */
+extern void enable_boot_trace(void);
+/* Suspend this tracing. Actually, only sched_switches tracing have
+ * to be suspended. Initcalls doesn't need it.)
+ */
+extern void disable_boot_trace(void);
static inline void trace_boot(struct boot_trace *it, initcall_t fn) { }
static inline void start_boot_trace(void) { }
-static inline void stop_boot_trace(void) { }
+static inline void enable_boot_trace(void) { }
+static inline void disable_boot_trace(void) { }