rcu: Deconfuse dynticks entry-exit tracing

The trace_rcu_dyntick() trace event did not print both the old and
the new value of the nesting level, and furthermore printed only
the low-order 32 bits of it.  This could result in some confusion
when interpreting trace-event dumps, so this commit prints both
the old and the new value, prints the full 64 bits, and also selects
the process-entry/exit increment to print nicely in hexadecimal.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index 172620a92b1a..c29fb2f55909 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -246,21 +246,24 @@ TRACE_EVENT(rcu_fqs,
  */
 TRACE_EVENT(rcu_dyntick,
 
-        TP_PROTO(char *polarity, int nesting),
+        TP_PROTO(char *polarity, long long oldnesting, long long newnesting),
 
-        TP_ARGS(polarity, nesting),
+        TP_ARGS(polarity, oldnesting, newnesting),
 
         TP_STRUCT__entry(
                 __field(char *, polarity)
-                __field(int, nesting)
+                __field(long long, oldnesting)
+                __field(long long, newnesting)
         ),
 
         TP_fast_assign(
                 __entry->polarity = polarity;
-                __entry->nesting = nesting;
+                __entry->oldnesting = oldnesting;
+                __entry->newnesting = newnesting;
         ),
 
-        TP_printk("%s %d", __entry->polarity, __entry->nesting)
+        TP_printk("%s %llx %llx", __entry->polarity,
+                  __entry->oldnesting, __entry->newnesting)
 );
 
 /*
@@ -470,7 +473,7 @@ TRACE_EVENT(rcu_torture_read,
 #define trace_rcu_unlock_preempted_task(rcuname, gpnum, pid) do { } while (0)
 #define trace_rcu_quiescent_state_report(rcuname, gpnum, mask, qsmask, level, grplo, grphi, gp_tasks) do { } while (0)
 #define trace_rcu_fqs(rcuname, gpnum, cpu, qsevent) do { } while (0)
-#define trace_rcu_dyntick(polarity, nesting) do { } while (0)
+#define trace_rcu_dyntick(polarity, oldnesting, newnesting) do { } while (0)
 #define trace_rcu_callback(rcuname, rhp, qlen) do { } while (0)
 #define trace_rcu_kfree_callback(rcuname, rhp, offset, qlen) do { } while (0)
 #define trace_rcu_batch_start(rcuname, qlen, blimit) do { } while (0)