From: Michal Sojka <sojkam1@fel.cvut.cz>
Date: Fri, 3 Dec 2010 16:13:47 +0000 (+0100)
Subject: Add ftrace support
X-Git-Tag: fix-allnoconfig~274
X-Git-Url: http://rtime.felk.cvut.cz/gitweb/can-benchmark.git/commitdiff_plain/107f1a1e7afc57354c570406d37f243c592f6ef8?hp=-c

Add ftrace support
---

107f1a1e7afc57354c570406d37f243c592f6ef8
diff --git a/latester/latester.c b/latester/latester.c
index f418567..9f0a466 100644
--- a/latester/latester.c
+++ b/latester/latester.c
@@ -35,6 +35,8 @@
 
 #include "histogram.h"
 
+//#define FTRACE
+
 #ifndef DEBUG
 #define dbg(level, fmt, arg...) do {} while (0)
 #else
@@ -278,6 +280,42 @@ static inline get_tstamp(struct timespec *ts)
 	clock_gettime(CLOCK_REALTIME, ts);
 }
 
+
+int trace_fd = -1;
+int marker_fd = -1;
+
+int init_ftrace()
+{
+#ifdef FTRACE
+	char *debugfs;
+	char path[256];
+	FILE *f;
+	
+	debugfs = "/sys/kernel/debug";
+	if (debugfs) {
+		strcpy(path, debugfs);
+		strcat(path,"/tracing/tracing_on");
+		trace_fd = open(path, O_WRONLY);
+		if (trace_fd >= 0)
+			write(trace_fd, "1", 1);
+
+		strcpy(path, debugfs);
+		strcat(path,"/tracing/trace_marker");
+		marker_fd = open(path, O_WRONLY);
+
+		strcpy(path, debugfs);
+		strcat(path,"/tracing/set_ftrace_pid");
+		f = fopen(path, "w");
+		fprintf(f, "%d\n", getpid());
+		fclose(f);
+		system("echo function_graph > /sys/kernel/debug/tracing/current_tracer");
+		system("echo can_send > /sys/kernel/debug/tracing/set_graph_function");
+		system("echo > /sys/kernel/debug/tracing/trace");
+		system("echo 1 > /sys/kernel/debug/tracing/tracing_enabled");
+	}
+#endif	/* FTRACE */
+}
+
 int send_frame(int socket)
 {
 	struct can_frame frame;
@@ -311,7 +349,17 @@ int send_frame(int socket)
 	mi->length = frame.can_dlc;
 	get_tstamp(&mi->ts_sent);
 	mi->sent = frame;
+	
+	if (trace_fd >= 0)
+		write(trace_fd, "1", 1);
 	ret = write(socket, &frame, sizeof(frame));
+	if (marker_fd >= 0) {
+		char marker[100];
+		sprintf(marker, "write returned %d\n", ret);
+		write(marker_fd, marker, strlen(marker));
+	}
+	if (trace_fd >= 0)
+		write(trace_fd, "0", 1);
 	return ret;
 }
 
@@ -627,6 +675,8 @@ int main(int argc, const char *argv[])
 	ret = fcntl(completion_pipe[1], F_SETFL, O_NONBLOCK);
 	if (ret == -1)
 		error(1, errno, "pipe fcntl");
+
+	init_ftrace();
 	
 	pthread_create(&thread, 0, measure_thread, NULL);