Commit 7ac1907c authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

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: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent e23344c2

kernel/rcu/tree.c

+0 −21
Original line number Diff line number Diff line
@@ -1031,27 +1031,6 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp) 
	return 0;

}



/*

 * 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

kernel/rcu/tree.h

+1 −0
Original line number Diff line number Diff line
@@ -443,4 +443,5 @@ 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);

kernel/rcu/tree_stall.h

+20 −0
Original line number Diff line number Diff line
@@ -139,6 +139,26 @@ 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

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