The field is used to keep track of the consecutive (on the same CPU) calls
of a single function. This information is needed in order to consolidate
the function tracing record in the cases when a single function is called
number of times.
Signed-off-by: Yordan Karadzhov (VMware) <y.kar...@gmail.com>
---
kernel/trace/trace.c | 1 +
kernel/trace/trace.h | 17 +++++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e295c413580e..5f5fa08c0644 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8895,6 +8895,7 @@ static int __remove_instance(struct trace_array *tr)
ftrace_clear_pids(tr);
ftrace_destroy_function_files(tr);
tracefs_remove(tr->dir);
+ free_percpu(tr->last_func_repeats);
free_trace_buffers(tr);
for (i = 0; i < tr->nr_topts; i++) {
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 2be4a56879de..09bf12c038f4 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -262,6 +262,16 @@ struct cond_snapshot {
cond_update_fn_t update;
};
+/*
+ * struct trace_func_repeats - used to keep track of the consecutive
+ * (on the same CPU) calls of a single function.
+ */
+struct trace_func_repeats {
+ unsigned long ip;
+ unsigned long parent_ip;
+ unsigned long count;
+};
+
/*
* The trace array - an array of per-CPU trace arrays. This is the
* highest level data structure that individual tracers deal with.
@@ -358,8 +368,15 @@ struct trace_array {
#ifdef CONFIG_TRACER_SNAPSHOT
struct cond_snapshot *cond_snapshot;
#endif
+ struct trace_func_repeats __percpu *last_func_repeats;
};
+static inline struct trace_func_repeats *
+tracer_alloc_func_repeats(struct trace_array *tr)
+{
+ return tr->last_func_repeats = alloc_percpu(struct trace_func_repeats);
+}
+
enum {
TRACE_ARRAY_FL_GLOBAL = (1 << 0)
};
--
2.25.1
