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: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c
index 7091d82..7649fcd 100644 (file)
--- a/kernel/rcu/rcu_segcblist.c
+++ b/kernel/rcu/rcu_segcblist.c
@@ -36,24 +36,6 @@ void rcu_cblist_init(struct rcu_cblist *rclp)
 }
 
 /*
- * 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
  * the caller can later invoke rcu_cblist_dequeued_lazy() if it
@@ -103,17 +85,6 @@ void rcu_segcblist_disable(struct rcu_segcblist *rsclp)
 }
 
 /*
- * 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?
  */
@@ -134,50 +105,6 @@ bool rcu_segcblist_pend_cbs(struct rcu_segcblist *rsclp)
 }
 
 /*
- * 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.
  */
@@ -203,17 +130,6 @@ struct rcu_head *rcu_segcblist_first_pend_cb(struct rcu_segcblist *rsclp)
 }
 
 /*
- * 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
  * field may be accessed locklessly, hence the WRITE_ONCE().

diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index c2f319f..581c12b 100644 (file)
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -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,