[PATCH 18/46] perf record: Use WARN_ONCE to replace 'if' condition

[Wang Nan]

Following commits will extract kernel and module synthesizing code into
a separated function and call it multiple times. This patch replace
'if (err < 0)' using WARN_ONCE, makes sure the error message show
one time.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
---
 tools/perf/builtin-record.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 7d11162..9dec7e5 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -33,6 +33,7 @@
 #include "util/parse-regs-options.h"
 #include "util/llvm-utils.h"
 #include "util/bpf-loader.h"
+#include "asm/bug.h"
 
 #include <unistd.h>
 #include <sched.h>
@@ -615,17 +616,15 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 
 	err = perf_event__synthesize_kernel_mmap(tool, process_synthesized_event,
 						 machine);
-	if (err < 0)
-		pr_err("Couldn't record kernel reference relocation symbol\n"
-		       "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
-		       "Check /proc/kallsyms permission or run as root.\n");
+	WARN_ONCE(err < 0, "Couldn't record kernel reference relocation symbol\n"
+			   "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
+			   "Check /proc/kallsyms permission or run as root.\n");
 
 	err = perf_event__synthesize_modules(tool, process_synthesized_event,
 					     machine);
-	if (err < 0)
-		pr_err("Couldn't record kernel module information.\n"
-		       "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
-		       "Check /proc/modules permission or run as root.\n");
+	WARN_ONCE(err < 0, "Couldn't record kernel module information.\n"
+			   "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
+			   "Check /proc/modules permission or run as root.\n");
 
 	if (perf_guest) {
 		machines__process_guests(&session->machines,
-- 
1.8.3.4