rcu: Move irq-disabled stall-warning checking to tree_stall.h
The rcu_iw_handler() function's sole purpose in life is to indicate
whether a stalled CPU had interrupts disabled, so it belongs in
kernel/rcu/tree_stall.h. This commit therefore makes that move,
clarifying its header comment while in the area.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f1afbb5c..9cda1b2 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1043,27 +1043,6 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp)
}
/*
- * Handler for the irq_work request posted when a grace period has
- * gone on for too long, but not yet long enough for an RCU CPU
- * stall warning. Set state appropriately, but just complain if
- * there is unexpected state on entry.
- */
-static void rcu_iw_handler(struct irq_work *iwp)
-{
- struct rcu_data *rdp;
- struct rcu_node *rnp;
-
- rdp = container_of(iwp, struct rcu_data, rcu_iw);
- rnp = rdp->mynode;
- raw_spin_lock_rcu_node(rnp);
- if (!WARN_ON_ONCE(!rdp->rcu_iw_pending)) {
- rdp->rcu_iw_gp_seq = rnp->gp_seq;
- rdp->rcu_iw_pending = false;
- }
- raw_spin_unlock_rcu_node(rnp);
-}
-
-/*
* Return true if the specified CPU has passed through a quiescent
* state by virtue of being in or having passed through an dynticks
* idle state since the last call to dyntick_save_progress_counter()
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index c71ffc5..f44dbd3 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -456,4 +456,5 @@ static void rcu_dynticks_task_exit(void);
/* Forward declarations for tree_stall.h */
static void record_gp_stall_check_time(void);
+static void rcu_iw_handler(struct irq_work *iwp);
static void check_cpu_stall(struct rcu_data *rdp);
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index ee953b1..5584ac8 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -161,6 +161,26 @@ static void rcu_stall_kick_kthreads(void)
}
}
+/*
+ * Handler for the irq_work request posted about halfway into the RCU CPU
+ * stall timeout, and used to detect excessive irq disabling. Set state
+ * appropriately, but just complain if there is unexpected state on entry.
+ */
+static void rcu_iw_handler(struct irq_work *iwp)
+{
+ struct rcu_data *rdp;
+ struct rcu_node *rnp;
+
+ rdp = container_of(iwp, struct rcu_data, rcu_iw);
+ rnp = rdp->mynode;
+ raw_spin_lock_rcu_node(rnp);
+ if (!WARN_ON_ONCE(!rdp->rcu_iw_pending)) {
+ rdp->rcu_iw_gp_seq = rnp->gp_seq;
+ rdp->rcu_iw_pending = false;
+ }
+ raw_spin_unlock_rcu_node(rnp);
+}
+
//////////////////////////////////////////////////////////////////////////////
//
// Printing RCU CPU stall warnings
