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Commit aed4e046 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Remove unused RCU list functions 



Given changes to callback migration, rcu_cblist_head(),
rcu_cblist_tail(), rcu_cblist_count_cbs(), rcu_segcblist_segempty(),
rcu_segcblist_dequeued_lazy(), and rcu_segcblist_new_cbs() are
no longer used.  This commit therefore removes them.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent f2dbe4a5

kernel/rcu/rcu_segcblist.c

+0 −84
Original line number Diff line number Diff line
@@ -35,24 +35,6 @@ void rcu_cblist_init(struct rcu_cblist *rclp) 
	rclp->len_lazy = 0;

}



/*

 * Debug function to actually count the number of callbacks.

 * If the number exceeds the limit specified, return -1.

 */

long rcu_cblist_count_cbs(struct rcu_cblist *rclp, long lim)

{

	int cnt = 0;

	struct rcu_head **rhpp = &rclp->head;



	for (;;) {

		if (!*rhpp)

			return cnt;

		if (++cnt > lim)

			return -1;

		rhpp = &(*rhpp)->next;

	}

}



/*

 * Dequeue the oldest rcu_head structure from the specified callback

 * list.  This function assumes that the callback is non-lazy, but
@@ -102,17 +84,6 @@ void rcu_segcblist_disable(struct rcu_segcblist *rsclp) 
	rsclp->tails[RCU_NEXT_TAIL] = NULL;

}



/*

 * Is the specified segment of the specified rcu_segcblist structure

 * empty of callbacks?

 */

bool rcu_segcblist_segempty(struct rcu_segcblist *rsclp, int seg)

{

	if (seg == RCU_DONE_TAIL)

		return &rsclp->head == rsclp->tails[RCU_DONE_TAIL];

	return rsclp->tails[seg - 1] == rsclp->tails[seg];

}



/*

 * Does the specified rcu_segcblist structure contain callbacks that

 * are ready to be invoked?
@@ -133,50 +104,6 @@ bool rcu_segcblist_pend_cbs(struct rcu_segcblist *rsclp) 
	       !rcu_segcblist_restempty(rsclp, RCU_DONE_TAIL);

}



/*

 * Dequeue and return the first ready-to-invoke callback.  If there

 * are no ready-to-invoke callbacks, return NULL.  Disables interrupts

 * to avoid interference.  Does not protect from interference from other

 * CPUs or tasks.

 */

struct rcu_head *rcu_segcblist_dequeue(struct rcu_segcblist *rsclp)

{

	unsigned long flags;

	int i;

	struct rcu_head *rhp;



	local_irq_save(flags);

	if (!rcu_segcblist_ready_cbs(rsclp)) {

		local_irq_restore(flags);

		return NULL;

	}

	rhp = rsclp->head;

	BUG_ON(!rhp);

	rsclp->head = rhp->next;

	for (i = RCU_DONE_TAIL; i < RCU_CBLIST_NSEGS; i++) {

		if (rsclp->tails[i] != &rhp->next)

			break;

		rsclp->tails[i] = &rsclp->head;

	}

	smp_mb(); /* Dequeue before decrement for rcu_barrier(). */

	WRITE_ONCE(rsclp->len, rsclp->len - 1);

	local_irq_restore(flags);

	return rhp;

}



/*

 * Account for the fact that a previously dequeued callback turned out

 * to be marked as lazy.

 */

void rcu_segcblist_dequeued_lazy(struct rcu_segcblist *rsclp)

{

	unsigned long flags;



	local_irq_save(flags);

	rsclp->len_lazy--;

	local_irq_restore(flags);

}



/*

 * Return a pointer to the first callback in the specified rcu_segcblist

 * structure.  This is useful for diagnostics.
@@ -202,17 +129,6 @@ struct rcu_head *rcu_segcblist_first_pend_cb(struct rcu_segcblist *rsclp) 
	return NULL;

}



/*

 * Does the specified rcu_segcblist structure contain callbacks that

 * have not yet been processed beyond having been posted, that is,

 * does it contain callbacks in its last segment?

 */

bool rcu_segcblist_new_cbs(struct rcu_segcblist *rsclp)

{

	return rcu_segcblist_is_enabled(rsclp) &&

	       !rcu_segcblist_restempty(rsclp, RCU_NEXT_READY_TAIL);

}



/*

 * Enqueue the specified callback onto the specified rcu_segcblist

 * structure, updating accounting as needed.  Note that the ->len

kernel/rcu/rcu_segcblist.h

+0 −26
Original line number Diff line number Diff line
@@ -31,29 +31,7 @@ static inline void rcu_cblist_dequeued_lazy(struct rcu_cblist *rclp) 
	rclp->len_lazy--;

}



/*

 * Interim function to return rcu_cblist head pointer.  Longer term, the

 * rcu_cblist will be used more pervasively, removing the need for this

 * function.

 */

static inline struct rcu_head *rcu_cblist_head(struct rcu_cblist *rclp)

{

	return rclp->head;

}



/*

 * Interim function to return rcu_cblist head pointer.  Longer term, the

 * rcu_cblist will be used more pervasively, removing the need for this

 * function.

 */

static inline struct rcu_head **rcu_cblist_tail(struct rcu_cblist *rclp)

{

	WARN_ON_ONCE(!rclp->head);

	return rclp->tail;

}



void rcu_cblist_init(struct rcu_cblist *rclp);

long rcu_cblist_count_cbs(struct rcu_cblist *rclp, long lim);

struct rcu_head *rcu_cblist_dequeue(struct rcu_cblist *rclp);



/*
@@ -134,14 +112,10 @@ static inline struct rcu_head **rcu_segcblist_tail(struct rcu_segcblist *rsclp) 


void rcu_segcblist_init(struct rcu_segcblist *rsclp);

void rcu_segcblist_disable(struct rcu_segcblist *rsclp);

bool rcu_segcblist_segempty(struct rcu_segcblist *rsclp, int seg);

bool rcu_segcblist_ready_cbs(struct rcu_segcblist *rsclp);

bool rcu_segcblist_pend_cbs(struct rcu_segcblist *rsclp);

struct rcu_head *rcu_segcblist_dequeue(struct rcu_segcblist *rsclp);

void rcu_segcblist_dequeued_lazy(struct rcu_segcblist *rsclp);

struct rcu_head *rcu_segcblist_first_cb(struct rcu_segcblist *rsclp);

struct rcu_head *rcu_segcblist_first_pend_cb(struct rcu_segcblist *rsclp);

bool rcu_segcblist_new_cbs(struct rcu_segcblist *rsclp);

void rcu_segcblist_enqueue(struct rcu_segcblist *rsclp,

			   struct rcu_head *rhp, bool lazy);

bool rcu_segcblist_entrain(struct rcu_segcblist *rsclp,