rcu: Remove dead code from rcu_segcblist_insert_pend_cbs()

paulmckrcu · paulmckrcu · commit 57721fd15a02 · 2020-02-20T15:58:23.000-08:00
The rcu_segcblist_insert_pend_cbs() function currently (partially)
initializes the rcu_cblist that it pulls callbacks from.  However, all
the resulting stores are dead because all callers pass in the address of
an on-stack cblist that is not used afterwards.  This commit therefore
removes this pointless initialization.

Signed-off-by: Paul E. McKenney &lt;paulmck@kernel.org&gt;
diff --git a/kernel/rcu/rcu_segcblist.c b/kernel/rcu/rcu_segcblist.c
@@ -381,8 +381,6 @@ void rcu_segcblist_insert_pend_cbs(struct rcu_segcblist *rsclp,
 		return; /* Nothing to do. */
 	WRITE_ONCE(*rsclp->tails[RCU_NEXT_TAIL], rclp->head);
 	WRITE_ONCE(rsclp->tails[RCU_NEXT_TAIL], rclp->tail);
-	rclp->head = NULL;
-	rclp->tail = &rclp->head;
 }
 
 /*

Original file line number	Diff line number	Diff line change
`@@ -381,8 +381,6 @@ void rcu_segcblist_insert_pend_cbs(struct rcu_segcblist *rsclp,`
`381`	`381`	`return; /* Nothing to do. */`
`382`	`382`	`WRITE_ONCE(*rsclp->tails[RCU_NEXT_TAIL], rclp->head);`
`383`	`383`	`WRITE_ONCE(rsclp->tails[RCU_NEXT_TAIL], rclp->tail);`
`384`		`- rclp->head = NULL;`
`385`		`- rclp->tail = &rclp->head;`
`386`	`384`	`}`
`387`	`385`
`388`	`386`	`/*`