[PATCH tip/core/rcu 30/52] rcu: Remove rsp parameter from __rcu_pending()

From: Paul E. McKenney
Date: Wed Aug 29 2018 - 18:40:02 EST


There now is only one rcu_state structure in a given build of the Linux
kernel, so there is no need to pass it as a parameter to RCU's functions.
This commit therefore removes the rsp parameter from __rcu_pending(),
and also inlines it into rcu_pending(), removing the for_each_rcu_flavor()
while in the neighborhood..

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 34 ++++++++++------------------------
1 file changed, 10 insertions(+), 24 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 4af227e826a6..e347a6b2984c 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2996,8 +2996,7 @@ EXPORT_SYMBOL_GPL(call_rcu_sched);
* callbacks in the list of pending callbacks. Until then, this
* function may only be called from __kfree_rcu().
*/
-void kfree_call_rcu(struct rcu_head *head,
- rcu_callback_t func)
+void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
{
__call_rcu(head, func, -1, 1);
}
@@ -3079,21 +3078,23 @@ void cond_synchronize_sched(unsigned long oldstate)
EXPORT_SYMBOL_GPL(cond_synchronize_sched);

/*
- * Check to see if there is any immediate RCU-related work to be done
- * by the current CPU, for the specified type of RCU, returning 1 if so.
- * The checks are in order of increasing expense: checks that can be
- * carried out against CPU-local state are performed first. However,
- * we must check for CPU stalls first, else we might not get a chance.
+ * Check to see if there is any immediate RCU-related work to be done by
+ * the current CPU, for the specified type of RCU, returning 1 if so and
+ * zero otherwise. The checks are in order of increasing expense: checks
+ * that can be carried out against CPU-local state are performed first.
+ * However, we must check for CPU stalls first, else we might not get
+ * a chance.
*/
-static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
+static int rcu_pending(void)
{
+ struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
struct rcu_node *rnp = rdp->mynode;

/* Check for CPU stalls, if enabled. */
check_cpu_stall(rdp);

/* Is this CPU a NO_HZ_FULL CPU that should ignore RCU? */
- if (rcu_nohz_full_cpu(rsp))
+ if (rcu_nohz_full_cpu(&rcu_state))
return 0;

/* Is the RCU core waiting for a quiescent state from this CPU? */
@@ -3123,21 +3124,6 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
return 0;
}

-/*
- * Check to see if there is any immediate RCU-related work to be done
- * by the current CPU, returning 1 if so. This function is part of the
- * RCU implementation; it is -not- an exported member of the RCU API.
- */
-static int rcu_pending(void)
-{
- struct rcu_state *rsp;
-
- for_each_rcu_flavor(rsp)
- if (__rcu_pending(rsp, this_cpu_ptr(&rcu_data)))
- return 1;
- return 0;
-}
-
/*
* Return true if the specified CPU has any callback. If all_lazy is
* non-NULL, store an indication of whether all callbacks are lazy.
--
2.17.1