rcutorture: Print symbolic name for ->gp_state

Currently, ->gp_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: Updated to fix relational operator called out by Dan Carpenter. ]
[ paulmck: More "const", as suggested by Josh Triplett. ]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 7b78c88e19a3..316354109734 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1187,6 +1187,16 @@ static void record_gp_stall_check_time(struct rcu_state *rsp)
 }
 
 /*
+ * Convert a ->gp_state value to a character string.
+ */
+static const char *gp_state_getname(short gs)
+{
+        if (gs < 0 || gs >= ARRAY_SIZE(gp_state_names))
+                return "???";
+        return gp_state_names[gs];
+}
+
+/*
  * Complain about starvation of grace-period kthread.
  */
 static void rcu_check_gp_kthread_starvation(struct rcu_state *rsp)
@@ -1197,10 +1207,11 @@ static void rcu_check_gp_kthread_starvation(struct rcu_state *rsp)
         j = jiffies;
         gpa = READ_ONCE(rsp->gp_activity);
         if (j - gpa > 2 * HZ) {
-                pr_err("%s kthread starved for %ld jiffies! g%lu c%lu f%#x s%d ->state=%#lx\n",
+                pr_err("%s kthread starved for %ld jiffies! g%lu c%lu f%#x %s(%d) ->state=%#lx\n",
                        rsp->name, j - gpa,
                        rsp->gpnum, rsp->completed,
-                       rsp->gp_flags, rsp->gp_state,
+                       rsp->gp_flags,
+                       gp_state_getname(rsp->gp_state), rsp->gp_state,
                        rsp->gp_kthread ? rsp->gp_kthread->state : ~0);
                 if (rsp->gp_kthread)
                         sched_show_task(rsp->gp_kthread);