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authorNamhyung Kim <namhyung@kernel.org>2016-08-31 04:55:29 +0200
committerSteven Rostedt <rostedt@goodmis.org>2016-09-01 18:19:40 +0200
commit8861dd303cba879bae9a9dcee74042fb642bf03b (patch)
tree9395c7c589d846cc94cbed3a960131fa15c72db4
parentfunction_graph: Handle TRACE_BPUTS in print_graph_comment (diff)
downloadlinux-8861dd303cba879bae9a9dcee74042fb642bf03b.tar.xz
linux-8861dd303cba879bae9a9dcee74042fb642bf03b.zip
ftrace: Access ret_stack->subtime only in the function profiler
The subtime is used only for function profiler with function graph tracer enabled. Move the definition of subtime under CONFIG_FUNCTION_PROFILER to reduce the memory usage. Also move the initialization of subtime into the graph entry callback. Link: http://lkml.kernel.org/r/20160831025529.24018-1-namhyung@kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--Documentation/trace/ftrace.txt10
-rw-r--r--include/linux/ftrace.h2
-rw-r--r--kernel/trace/ftrace.c6
-rw-r--r--kernel/trace/trace_functions_graph.c1
4 files changed, 13 insertions, 6 deletions
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index a6b3705e62a6..185c39fea2a0 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -858,11 +858,11 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
When enabled, it will account time the task has been
scheduled out as part of the function call.
- graph-time - When running function graph tracer, to include the
- time to call nested functions. When this is not set,
- the time reported for the function will only include
- the time the function itself executed for, not the time
- for functions that it called.
+ graph-time - When running function profiler with function graph tracer,
+ to include the time to call nested functions. When this is
+ not set, the time reported for the function will only
+ include the time the function itself executed for, not the
+ time for functions that it called.
record-cmd - When any event or tracer is enabled, a hook is enabled
in the sched_switch trace point to fill comm cache
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 7d565afe35d2..1e2b316d6693 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -794,7 +794,9 @@ struct ftrace_ret_stack {
unsigned long ret;
unsigned long func;
unsigned long long calltime;
+#ifdef CONFIG_FUNCTION_PROFILER
unsigned long long subtime;
+#endif
unsigned long fp;
};
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 84752c8e28b5..2050a7652a86 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -872,7 +872,13 @@ function_profile_call(unsigned long ip, unsigned long parent_ip,
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int profile_graph_entry(struct ftrace_graph_ent *trace)
{
+ int index = trace->depth;
+
function_profile_call(trace->func, 0, NULL, NULL);
+
+ if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
+ current->ret_stack[index].subtime = 0;
+
return 1;
}
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index e14017c36170..148c90f1e49b 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -170,7 +170,6 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
current->ret_stack[index].ret = ret;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = calltime;
- current->ret_stack[index].subtime = 0;
current->ret_stack[index].fp = frame_pointer;
*depth = current->curr_ret_stack;