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-rw-r--r--kernel/rcu/tree.c12
-rw-r--r--kernel/sysctl.c11
2 files changed, 23 insertions, 0 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index c844b6142a86..e5ca15a461b9 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -125,6 +125,8 @@ int rcu_num_lvls __read_mostly = RCU_NUM_LVLS;
/* Number of rcu_nodes at specified level. */
static int num_rcu_lvl[] = NUM_RCU_LVL_INIT;
int rcu_num_nodes __read_mostly = NUM_RCU_NODES; /* Total # rcu_nodes in use. */
+/* panic() on RCU Stall sysctl. */
+int sysctl_panic_on_rcu_stall __read_mostly;
/*
* The rcu_scheduler_active variable transitions from zero to one just
@@ -1312,6 +1314,12 @@ static void rcu_stall_kick_kthreads(struct rcu_state *rsp)
}
}
+static inline void panic_on_rcu_stall(void)
+{
+ if (sysctl_panic_on_rcu_stall)
+ panic("RCU Stall\n");
+}
+
static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
{
int cpu;
@@ -1391,6 +1399,8 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
rcu_check_gp_kthread_starvation(rsp);
+ panic_on_rcu_stall();
+
force_quiescent_state(rsp); /* Kick them all. */
}
@@ -1431,6 +1441,8 @@ static void print_cpu_stall(struct rcu_state *rsp)
jiffies + 3 * rcu_jiffies_till_stall_check() + 3);
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
+ panic_on_rcu_stall();
+
/*
* Attempt to revive the RCU machinery by forcing a context switch.
*
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 87b2fc38398b..35f0dcb1cb4f 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1205,6 +1205,17 @@ static struct ctl_table kern_table[] = {
.extra2 = &one,
},
#endif
+#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
+ {
+ .procname = "panic_on_rcu_stall",
+ .data = &sysctl_panic_on_rcu_stall,
+ .maxlen = sizeof(sysctl_panic_on_rcu_stall),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+#endif
{ }
};