[PATCH 5/9] perf tools: Add pr_warning_once debug macro

[Jiri Olsa <jolsa@kernel.org>]

Adding pr_warning_once debug macro to display
pr_warning message just once. It will be used
in following patch.

Cc: Andi Kleen <andi@firstfloor.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jen-Cheng(Tommy) Huang <tommy24@gatech.edu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/debug.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
index be264d6f3b30..be0399c2703d 100644
--- a/tools/perf/util/debug.h
+++ b/tools/perf/util/debug.h
@@ -31,6 +31,18 @@ extern int debug_ordered_events;
 #define pr_debug3(fmt, ...) pr_debugN(3, pr_fmt(fmt), ##__VA_ARGS__)
 #define pr_debug4(fmt, ...) pr_debugN(4, pr_fmt(fmt), ##__VA_ARGS__)
 
+#define pr_once(fmt, pr, ...)			\
+	do {					\
+		static int __warned;		\
+						\
+		if (!__warned) {		\
+			pr(fmt, ##__VA_ARGS__);	\
+			__warned = 1;		\
+		}				\
+	} while (0)
+
+#define pr_warning_once(fmt, ...) pr_once(fmt, pr_warning, ##__VA_ARGS__)
+
 #define pr_time_N(n, var, t, fmt, ...) \
 	eprintf_time(n, var, t, fmt, ##__VA_ARGS__)
 
-- 
1.8.3.1