Attempt to ignore ENOBUFS error

[can-benchmark.git] / latester / latester.c

diff --git a/latester/latester.c b/latester/latester.c
index cb578a11ed716ad591198df47fe7b1acb27199fb..b3f20029becb8c67e55f9bf95183c7cd9491e8b7 100644 (file)
--- 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
@@ -60,6 +62,7 @@ struct options {
        FILE *file;
        FILE *histogram;
        int length;
+       int userhist;
 };
 
 struct options opt = {
@@ -228,9 +231,15 @@ static inline unsigned get_msg_latency_us(struct msg_info *mi)
 {
        struct timespec diff;
        if (num_interfaces == 3)
-               timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
+               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_sent);
+               if (opt.userhist)
+                       timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
+               else
+                       timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_sent);
        return diff.tv_sec * 1000000 + diff.tv_nsec/1000;
 }
 
@@ -268,7 +277,65 @@ static inline int sock_get_if_index(int s, const char *if_name)
 
 static inline get_tstamp(struct timespec *ts)
 {
-       clock_gettime(CLOCK_MONOTONIC, 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)
@@ -304,13 +371,14 @@ 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)
@@ -466,13 +534,19 @@ void *measure_thread(void *arg)
 
        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++;                      \
+#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) { \
+                               /* 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) {
@@ -546,6 +620,7 @@ struct poptOption optionsTable[] = {
        { "file",   'f', POPT_ARG_STRING,                         NULL, 'f',         "File where to store results", "filename"},
        { "histogram", 'h', POPT_ARG_STRING,                      NULL, 'h',         "Store histogram in file", "filename"},
        { "length", 'l', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT,  &opt.length, 0,    "The length of generated messages", "bytes"},
+       { "userhist", 'u', POPT_ARG_NONE,                         &opt.userhist, 0,  "Generate histogram from userspace timestamps"},
        POPT_AUTOHELP
        { NULL, 0, 0, NULL, 0 }
 };
@@ -619,6 +694,8 @@ 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);