X-Git-Url: http://rtime.felk.cvut.cz/gitweb/can-benchmark.git/blobdiff_plain/4d12a04740d8e01ce0e9f6129487a6efd456229b..cf9bd660b3c10cff6e81af6fb4e42d3569229514:/latester/latester.c

diff --git a/latester/latester.c b/latester/latester.c
index f418567..c980f24 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
@@ -70,6 +72,11 @@ struct options opt = {
 	.length = 2,
 };
 
+struct {
+	unsigned enobufs;
+	unsigned overrun;
+} stats;
+
 int num_interfaces = 0;
 int count = 0;			/* Number of sent messages */
 int completion_pipe[2];
@@ -230,9 +237,9 @@ static inline unsigned get_msg_latency_us(struct msg_info *mi)
 	struct timespec diff;
 	if (num_interfaces == 3)
 		if (opt.userhist)
-			timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
-		else
 			timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_rx_onwire);
+		else
+			timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
 	else
 		if (opt.userhist)
 			timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
@@ -278,6 +285,64 @@ 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 */
+}
+
+static inline void trace_on()
+{
+	if (trace_fd >= 0)
+		write(trace_fd, "1", 1);
+}
+
+static inline void trace_off(int ret)
+{
+	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);
+}
+
+void msg_info_free(struct msg_info *mi)
+{
+	mi->id = -1;
+}
+
 int send_frame(int socket)
 {
 	struct can_frame frame;
@@ -311,13 +376,14 @@ int send_frame(int socket)
 	mi->length = frame.can_dlc;
 	get_tstamp(&mi->ts_sent);
 	mi->sent = frame;
+	
+	trace_on();
 	ret = write(socket, &frame, sizeof(frame));
-	return ret;
-}
+	trace_off(ret);
 
-void msg_info_free(struct msg_info *mi)
-{
-	mi->id = -1;
+	if (ret == -1)
+		msg_info_free(mi);
+	return ret;
 }
 
 static inline void get_next_timeout(struct timespec *timeout)
@@ -336,7 +402,10 @@ static inline void get_next_timeout(struct timespec *timeout)
 			last.tv_nsec -= 1000000000;
 			last.tv_sec++;
 		}
-		timespec_subtract(timeout, &last, &now);
+		if (timespec_subtract(timeout, &last, &now) /* is negative */) {
+			stats.overrun++;
+			memset(timeout, 0, sizeof(*timeout));
+		}
 	} else if (opt.timeout_ms != 0) {
 		timeout->tv_sec = opt.timeout_ms/1000;
 		timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
@@ -471,15 +540,22 @@ void *measure_thread(void *arg)
 			pfd[i].events = POLLIN;
 	}
 
-	set_sched_policy_and_prio(SCHED_FIFO, 99);
-
-#define SEND()						\
-	do {						\
-		ret = send_frame(pfd[0].fd);		\
-		if (ret != sizeof(struct can_frame))	\
-			error(1, errno, "send_frame (line %d)", __LINE__); \
-		count++;				\
-		msg_in_progress++;			\
+	set_sched_policy_and_prio(SCHED_FIFO, 40);
+
+#define SEND()								\
+	do {								\
+		ret = send_frame(pfd[0].fd);				\
+		if (ret != sizeof(struct can_frame)) {			\
+			if (ret == -1 && errno == ENOBUFS && opt.period_us == 0 && !opt.oneattime) { \
+				stats.enobufs++;			\
+				/* Ignore this error - pfifo_fast qeuue is full */ \
+			} else						\
+				error(1, errno, "send_frame (line %d)", __LINE__); \
+		}							\
+		else {							\
+			count++;					\
+			msg_in_progress++;				\
+		}							\
 	} while (0)
 
 	if (opt.oneattime) {
@@ -627,6 +703,8 @@ 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);
 
@@ -677,5 +755,10 @@ int main(int argc, const char *argv[])
 	if (opt.file)
 		fclose(opt.file);
 
+	if (stats.overrun)
+		printf("overrun=%d\n", stats.overrun);
+	if (stats.enobufs)
+		printf("enobufs=%d\n", stats.enobufs);
+
 	return 0;
 }