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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2015-03-31 14:37:12 -0400
committerSteven Rostedt <rostedt@goodmis.org>2015-04-08 09:39:55 -0400
commitacd388fd3af350ab24c6ab6f19b83fc4a4f3aa60 (patch)
tree98b1345299c3ea060b8297b35465d4dc92e4ea1d
parent6e9dd8ddbdbb3b7aeba7fd9b987579534cfc260b (diff)
downloadlinux-acd388fd3af350ab24c6ab6f19b83fc4a4f3aa60.tar.bz2
tracing: Give system name a pointer
Normally the compiler will use the same pointer for a string throughout the file. But there's no guarantee of that happening. Later changes will require that all events have the same pointer to the system string. Name the system string and have all events point to it. Testing this, it did not increases the size of the text, except for the notes section, which should not harm the real size any. Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--include/linux/ftrace_event.h2
-rw-r--r--include/trace/ftrace.h19
2 files changed, 18 insertions, 3 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index c674ee8f7fca..62b8fac7ded5 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -202,7 +202,7 @@ enum trace_reg {
struct ftrace_event_call;
struct ftrace_event_class {
- char *system;
+ const char *system;
void *probe;
#ifdef CONFIG_PERF_EVENTS
void *perf_probe;
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 41bf65f04dd9..2f9b95b6d3fb 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -18,6 +18,21 @@
#include <linux/ftrace_event.h>
+#ifndef TRACE_SYSTEM_VAR
+#define TRACE_SYSTEM_VAR TRACE_SYSTEM
+#endif
+
+#define __app__(x, y) str__##x##y
+#define __app(x, y) __app__(x, y)
+
+#define TRACE_SYSTEM_STRING __app(TRACE_SYSTEM_VAR,__trace_system_name)
+
+#define TRACE_MAKE_SYSTEM_STR() \
+ static const char TRACE_SYSTEM_STRING[] = \
+ __stringify(TRACE_SYSTEM)
+
+TRACE_MAKE_SYSTEM_STR();
+
/*
* DECLARE_EVENT_CLASS can be used to add a generic function
* handlers for events. That is, if all events have the same
@@ -105,7 +120,6 @@
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
-
/*
* Stage 2 of the trace events.
*
@@ -692,7 +706,7 @@ static inline void ftrace_test_probe_##call(void) \
_TRACE_PERF_PROTO(call, PARAMS(proto)); \
static const char print_fmt_##call[] = print; \
static struct ftrace_event_class __used __refdata event_class_##call = { \
- .system = __stringify(TRACE_SYSTEM), \
+ .system = TRACE_SYSTEM_STRING, \
.define_fields = ftrace_define_fields_##call, \
.fields = LIST_HEAD_INIT(event_class_##call.fields),\
.raw_init = trace_event_raw_init, \
@@ -735,6 +749,7 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+#undef TRACE_SYSTEM_VAR
#ifdef CONFIG_PERF_EVENTS