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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2013-07-18 20:41:51 +0200
committerSteven Rostedt <rostedt@goodmis.org>2013-07-19 03:31:31 +0200
commit8f768993394a8c0d3801033c11fd86ce8c88dcac (patch)
tree67321d3042a7561729c55763190ffde07336904a /kernel/trace/trace.h
parenttracing: Miscellaneous fixes for trace_array ref counting (diff)
downloadlinux-8f768993394a8c0d3801033c11fd86ce8c88dcac.tar.xz
linux-8f768993394a8c0d3801033c11fd86ce8c88dcac.zip
tracing: Add ref_data to function and fgraph tracer structs
The selftest for function and function graph tracers are defined as __init, as they are only executed at boot up. The "tracer" structs that are associated to those tracers are not setup as __init as they are used after boot. To stop mismatch warnings, those structures need to be annotated with __ref_data. Currently, the tracer structures are defined to __read_mostly, as they do not really change. But in the future they should be converted to consts, but that will take a little work because they have a "next" pointer that gets updated when they are registered. That will have to wait till the next major release. Link: http://lkml.kernel.org/r/1373596735.17876.84.camel@gandalf.local.home Reported-by: kbuild test robot <fengguang.wu@intel.com> Reported-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
-rw-r--r--kernel/trace/trace.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 4a4f6e1828b6..57b7bb0d39b7 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -680,6 +680,15 @@ extern int trace_selftest_startup_sched_switch(struct tracer *trace,
struct trace_array *tr);
extern int trace_selftest_startup_branch(struct tracer *trace,
struct trace_array *tr);
+/*
+ * Tracer data references selftest functions that only occur
+ * on boot up. These can be __init functions. Thus, when selftests
+ * are enabled, then the tracers need to reference __init functions.
+ */
+#define __tracer_data __refdata
+#else
+/* Tracers are seldom changed. Optimize when selftests are disabled. */
+#define __tracer_data __read_mostly
#endif /* CONFIG_FTRACE_STARTUP_TEST */
extern void *head_page(struct trace_array_cpu *data);