rcutorture: Make rcuperf collect expedited event-trace data

This commit enables ftrace in the rcuperf TREE kernel build and adds
an ftrace_dump() at the end of rcuperf processing.  This data will be
used to measure the actual durations of the expedited grace periods
without the added delays inherent in the kernel-module measurements.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

2 files changed, 2 insertions, 0 deletions

diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index e18d016a9888..12561f96f0a2 100644
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -404,6 +404,7 @@ rcu_perf_writer(void *arg)
                                  perf_type, me, MIN_MEAS);
                         if (atomic_inc_return(&n_rcu_perf_writer_finished) >=
                             nrealwriters) {
+                                rcu_ftrace_dump(DUMP_ALL);
                                 PERFOUT_STRING("Test complete");
                                 t_rcu_perf_writer_finished = t;
                                 if (gp_exp) {
diff --git a/tools/testing/selftests/rcutorture/configs/rcuperf/TREE b/tools/testing/selftests/rcutorture/configs/rcuperf/TREE
index 614e107f6db5..a312f671a29a 100644
--- a/tools/testing/selftests/rcutorture/configs/rcuperf/TREE
+++ b/tools/testing/selftests/rcutorture/configs/rcuperf/TREE
@@ -17,3 +17,4 @@ CONFIG_PROVE_LOCKING=n
 CONFIG_RCU_BOOST=n
 CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
 CONFIG_RCU_EXPERT=y
+CONFIG_RCU_TRACE=y