trace-cmd: Show ring buffer stastics at the end of tracing

When the tracer is completed, show the ring buffer statistics to
give a good idea about overruns and such.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

3 files changed, 51 insertions, 0 deletions

diff --git a/trace-cmd.c b/trace-cmd.c
index 92008cd..879d9ad 100644
--- a/trace-cmd.c
+++ b/trace-cmd.c
@@ -673,6 +673,7 @@ int main (int argc, char **argv)
         const char *output = NULL;
         const char *option;
         struct event_list *event;
+        struct trace_seq s;
         int disable = 0;
         int plug = 0;
         int events = 0;
@@ -680,6 +681,7 @@ int main (int argc, char **argv)
         int record = 0;
         int run_command = 0;
         int fset;
+        int cpu;
 
         int c;
 
@@ -852,6 +854,15 @@ int main (int argc, char **argv)
         record_data();
         delete_thread_data();
 
+        printf("Buffer statistics:\n\n");
+        for (cpu = 0; cpu < cpu_count; cpu++) {
+                trace_seq_init(&s);
+                trace_seq_printf(&s, "CPU: %d\n", cpu);
+                tracecmd_stat_cpu(&s, cpu);
+                trace_seq_do_printf(&s);
+                printf("\n");
+        }
+
         exit(0);
 
         return 0;
diff --git a/trace-cmd.h b/trace-cmd.h
index 27f30a7..4410f4c 100644
--- a/trace-cmd.h
+++ b/trace-cmd.h
@@ -109,6 +109,7 @@ void tracecmd_free_recorder(struct tracecmd_recorder *recorder);
 struct tracecmd_recorder *tracecmd_create_recorder(const char *file, int cpu);
 int tracecmd_start_recording(struct tracecmd_recorder *recorder, unsigned long sleep);
 void tracecmd_stop_recording(struct tracecmd_recorder *recorder);
+void tracecmd_stat_cpu(struct trace_seq *s, int cpu);
 
 
 #endif /* _TRACE_CMD_H */
diff --git a/trace-record.c b/trace-record.c
index 96579f1..6c910c7 100644
--- a/trace-record.c
+++ b/trace-record.c
@@ -138,3 +138,42 @@ void tracecmd_stop_recording(struct tracecmd_recorder *recorder)
 
         recorder->stop = 1;
 }
+
+/**
+ * tracecmd_stat_cpu - show the buffer stats of a particular CPU
+ * @s: the trace_seq to record the data in.
+ * @cpu: the CPU to stat
+ *
+ */
+void tracecmd_stat_cpu(struct trace_seq *s, int cpu)
+{
+        char buf[BUFSIZ];
+        char *tracing;
+        char *path;
+        int fd;
+        int r;
+
+        tracing = tracecmd_find_tracing_dir();
+        if (!tracing) {
+                errno = ENODEV;
+                goto out_free;
+        }
+
+        path = malloc_or_die(strlen(tracing) + 40);
+        if (!path)
+                goto out_free;
+
+        sprintf(path, "%s/per_cpu/cpu%d/stats", tracing, cpu);
+        fd = open(path, O_RDONLY);
+        if (fd < 0)
+                goto out_free;
+
+        while ((r = read(fd, buf, BUFSIZ)) > 0)
+                trace_seq_printf(s, "%.*s", r, buf);
+
+        close(fd);
+
+ out_free:
+        free(path);
+        free(tracing);
+}