rcu: Shrink each possible cpu krcp

CPUs can go offline shortly after kfree_call_rcu() has been invoked,
which can leave memory stranded until those CPUs come back online.
This commit therefore drains the kcrp of each CPU, not just the
ones that happen to be online.

Acked-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 2323622936788993667c183d64e09484c007f4d2..92450642c4d8cbbe699f93310577ec32d017623f 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3450,7 +3450,7 @@ kfree_rcu_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
        unsigned long count = 0;
 
        /* Snapshot count of all CPUs */
-       for_each_online_cpu(cpu) {
+       for_each_possible_cpu(cpu) {
                struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
 
                count += READ_ONCE(krcp->count);
@@ -3465,7 +3465,7 @@ kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
        int cpu, freed = 0;
        unsigned long flags;
 
-       for_each_online_cpu(cpu) {
+       for_each_possible_cpu(cpu) {
                int count;
                struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
 
@@ -3498,7 +3498,7 @@ void __init kfree_rcu_scheduler_running(void)
        int cpu;
        unsigned long flags;
 
-       for_each_online_cpu(cpu) {
+       for_each_possible_cpu(cpu) {
                struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
 
                raw_spin_lock_irqsave(&krcp->lock, flags);