net/neighbour: queue work on power efficient wq

Workqueue used in neighbour layer have no real dependency of scheduling these on
the cpu which scheduled them.

On a idle system, it is observed that an idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which the
scheduler believes to be the most appropriate one.

This patch replaces normal workqueues with power efficient versions. This
doesn't change existing behavior of code unless CONFIG_WQ_POWER_EFFICIENT is
enabled.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index f8012feddf6d..b9e9e0d38672 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -828,7 +828,7 @@ out:
          * ARP entry timeouts range from 1/2 BASE_REACHABLE_TIME to 3/2
          * BASE_REACHABLE_TIME.
          */
-        schedule_delayed_work(&tbl->gc_work,
+        queue_delayed_work(system_power_efficient_wq, &tbl->gc_work,
                               NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1);
         write_unlock_bh(&tbl->lock);
 }
@@ -1565,7 +1565,8 @@ static void neigh_table_init_no_netlink(struct neigh_table *tbl)
 
         rwlock_init(&tbl->lock);
         INIT_DEFERRABLE_WORK(&tbl->gc_work, neigh_periodic_work);
-        schedule_delayed_work(&tbl->gc_work, tbl->parms.reachable_time);
+        queue_delayed_work(system_power_efficient_wq, &tbl->gc_work,
+                        tbl->parms.reachable_time);
         setup_timer(&tbl->proxy_timer, neigh_proxy_process, (unsigned long)tbl);
         skb_queue_head_init_class(&tbl->proxy_queue,
                         &neigh_table_proxy_queue_class);