add support for tracing IPI latency

2 files changed, 30 insertions, 5 deletions

diff --git a/include/litmus/trace.h b/include/litmus/trace.h
index 620d1ac303..e8e0c7b6cc 100644
--- a/include/litmus/trace.h
+++ b/include/litmus/trace.h
@@ -27,12 +27,18 @@ struct timestamp {
 feather_callback void save_timestamp(unsigned long event);
 feather_callback void save_timestamp_def(unsigned long event, unsigned long type);
 feather_callback void save_timestamp_task(unsigned long event, unsigned long t_ptr);
+feather_callback void save_timestamp_cpu(unsigned long event, unsigned long cpu);
+
 
 #define TIMESTAMP(id) ft_event0(id, save_timestamp)
 
 #define DTIMESTAMP(id, def)  ft_event1(id, save_timestamp_def, def)
 
-#define TTIMESTAMP(id, task) ft_event1(id, save_timestamp_task, (unsigned long) task)
+#define TTIMESTAMP(id, task) \
+        ft_event1(id, save_timestamp_task, (unsigned long) task)
+
+#define CTIMESTAMP(id, cpu) \
+        ft_event1(id, save_timestamp_cpu, cpu)
 
 #else /* !CONFIG_SCHED_OVERHEAD_TRACE */
 
@@ -42,6 +48,8 @@ feather_callback void save_timestamp_task(unsigned long event, unsigned long t_p
 
 #define TTIMESTAMP(id, task) /* no tracing */
 
+#define CTIMESTAMP(id, cpu)  /* no tracing */
+
 #endif
 
 
@@ -98,6 +106,8 @@ feather_callback void save_timestamp_task(unsigned long event, unsigned long t_p
 #define TS_FIFO_DOWN_START              TIMESTAMP(182)
 #define TS_FIFO_DOWN_END                TIMESTAMP(183)
 
+#define TS_SEND_RESCHED_START(c)        CTIMESTAMP(190, c)
+#define TS_SEND_RESCHED_END             DTIMESTAMP(191, TSK_UNKNOWN)
 
 
 #endif /* !_SYS_TRACE_H_ */
diff --git a/litmus/trace.c b/litmus/trace.c
index 8851198330..6a134121e1 100644
--- a/litmus/trace.c
+++ b/litmus/trace.c
@@ -14,7 +14,8 @@ static struct ftdev overhead_dev;
 
 static unsigned int ts_seq_no = 0;
 
-static inline void __save_timestamp(unsigned long event, uint8_t type)
+static inline void __save_timestamp_cpu(unsigned long event,
+                                        uint8_t type, uint8_t cpu)
 {
         unsigned int seq_no;
         struct timestamp *ts;
@@ -23,28 +24,42 @@ static inline void __save_timestamp(unsigned long event, uint8_t type)
                 ts->event     = event;
                 ts->timestamp = ft_timestamp();
                 ts->seq_no    = seq_no;
-                ts->cpu       = raw_smp_processor_id();
+                ts->cpu       = cpu;
                 ts->task_type = type;
                 ft_buffer_finish_write(trace_ts_buf, ts);
         }
 }
 
+static inline void __save_timestamp(unsigned long event,
+                                   uint8_t type)
+{
+        __save_timestamp_cpu(event, type, raw_smp_processor_id());
+}
+
 feather_callback void save_timestamp(unsigned long event)
 {
         __save_timestamp(event, TSK_UNKNOWN);
 }
 
-feather_callback void save_timestamp_def(unsigned long event, unsigned long type)
+feather_callback void save_timestamp_def(unsigned long event,
+                                         unsigned long type)
 {
         __save_timestamp(event, (uint8_t) type);
 }
 
-feather_callback void save_timestamp_task(unsigned long event, unsigned long t_ptr)
+feather_callback void save_timestamp_task(unsigned long event,
+                                          unsigned long t_ptr)
 {
         int rt = is_realtime((struct task_struct *) t_ptr);
         __save_timestamp(event, rt ? TSK_RT : TSK_BE);
 }
 
+feather_callback void save_timestamp_cpu(unsigned long event,
+                                         unsigned long cpu)
+{
+        __save_timestamp_cpu(event, TSK_UNKNOWN, cpu);
+}
+
 /******************************************************************************/
 /*                        DEVICE FILE DRIVER                                  */
 /******************************************************************************/