rcutorture: Print symbolic name for rcu_torture_writer_state

Currently, rcu_torture_writer_state is printed as an integer, which slows
debugging.  This commit therefore prints a symbolic name in addition to
the integer.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: More "const", as suggested by Josh Triplett. ]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index d89328e..d2988d0 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -162,6 +162,27 @@ static int rcu_torture_writer_state;
 #define RTWS_SYNC              7
 #define RTWS_STUTTER           8
 #define RTWS_STOPPING          9
+static const char * const rcu_torture_writer_state_names[] = {
+       "RTWS_FIXED_DELAY",
+       "RTWS_DELAY",
+       "RTWS_REPLACE",
+       "RTWS_DEF_FREE",
+       "RTWS_EXP_SYNC",
+       "RTWS_COND_GET",
+       "RTWS_COND_SYNC",
+       "RTWS_SYNC",
+       "RTWS_STUTTER",
+       "RTWS_STOPPING",
+};
+
+static const char *rcu_torture_writer_state_getname(void)
+{
+       unsigned int i = READ_ONCE(rcu_torture_writer_state);
+
+       if (i >= ARRAY_SIZE(rcu_torture_writer_state_names))
+               return "???";
+       return rcu_torture_writer_state_names[i];
+}
 
 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
 #define RCUTORTURE_RUNNABLE_INIT 1
@@ -1307,7 +1328,8 @@ rcu_torture_stats_print(void)
 
                rcutorture_get_gp_data(cur_ops->ttype,
                                       &flags, &gpnum, &completed);
-               pr_alert("??? Writer stall state %d g%lu c%lu f%#x\n",
+               pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x\n",
+                        rcu_torture_writer_state_getname(),
                         rcu_torture_writer_state,
                         gpnum, completed, flags);
                show_rcu_gp_kthreads();