[PATCH 2/2] net/neighbour: queue work on power efficient wq

From: Viresh Kumar
Date: Wed Jan 22 2014 - 01:54:44 EST

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

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
net/core/neighbour.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index f8012fe..b9e9e0d 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
- schedule_delayed_work(&tbl->gc_work,
+ queue_delayed_work(system_power_efficient_wq, &tbl->gc_work,
NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1);
@@ -1565,7 +1565,8 @@ static void neigh_table_init_no_netlink(struct neigh_table *tbl)

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);

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