[PATCH v2 1/6] trace-cmd library: Add log levels

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

Add levels to library logs and introduce a new API to set the desired
log severity:
 tracecmd_set_loglevel()
When a new trace-cmd library log level is set, propagate it to tracefs
and traceevent libraries as well.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 include/trace-cmd/trace-cmd.h |  2 ++
 lib/trace-cmd/trace-util.c    | 24 ++++++++++++++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 7305487c..6984db86 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -43,4 +43,6 @@ int tracecmd_buffer_instances(struct tracecmd_input *handle);
 const char *tracecmd_buffer_instance_name(struct tracecmd_input *handle, int indx);
 struct tracecmd_input *tracecmd_buffer_instance_handle(struct tracecmd_input *handle, int indx);
 
+void tracecmd_set_loglevel(enum tep_loglevel level);
+
 #endif /* _TRACE_CMD_H */
diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c
index 049fe049..6db754e4 100644
--- a/lib/trace-cmd/trace-util.c
+++ b/lib/trace-cmd/trace-util.c
@@ -30,7 +30,7 @@
 #define PROC_STACK_FILE "/proc/sys/kernel/stack_tracer_enabled"
 
 static bool debug;
-
+static int log_level = TEP_LOG_CRITICAL;
 static FILE *logfp;
 
 const static struct {
@@ -355,19 +355,36 @@ trace_load_plugins(struct tep_handle *tep, int flags)
 	return list;
 }
 
+/**
+ * tracecmd_set_loglevel - set log level of the library
+ * @level: desired level of the library messages
+ */
+void tracecmd_set_loglevel(enum tep_loglevel level)
+{
+	log_level = level;
+	tracefs_set_loglevel(level);
+	tep_set_loglevel(level);
+}
+
 void __weak tracecmd_warning(const char *fmt, ...)
 {
 	va_list ap;
 
+	if (log_level < TEP_LOG_WARNING)
+		return;
+
 	va_start(ap, fmt);
 	tep_vprint("libtracecmd", TEP_LOG_WARNING, true, fmt, ap);
 	va_end(ap);
 }
 
-void tracecmd_info(const char *fmt, ...)
+void __weak tracecmd_info(const char *fmt, ...)
 {
 	va_list ap;
 
+	if (log_level < TEP_LOG_INFO)
+		return;
+
 	va_start(ap, fmt);
 	tep_vprint("libtracecmd", TEP_LOG_INFO, false, fmt, ap);
 	va_end(ap);
@@ -379,6 +396,9 @@ void __weak tracecmd_fatal(const char *fmt, ...)
 	int ret;
 	va_list ap;
 
+	if (log_level < TEP_LOG_CRITICAL)
+		return;
+
 	va_start(ap, fmt);
 	ret = tep_vprint("libtracecmd", TEP_LOG_CRITICAL, true, fmt, ap);
 	va_end(ap);
-- 
2.31.1