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>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index f8012fe..b9e9e0d 100644 (file)
--- 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);