net/ipv4: queue work on power efficient wq

Workqueue used in ipv4 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, 6 insertions, 4 deletions

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 646023bd5449..ac2dff3c2c1c 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -474,7 +474,7 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
         inet_hash_insert(dev_net(in_dev->dev), ifa);
 
         cancel_delayed_work(&check_lifetime_work);
-        schedule_delayed_work(&check_lifetime_work, 0);
+        queue_delayed_work(system_power_efficient_wq, &check_lifetime_work, 0);
 
         /* Send message first, then call notifier.
            Notifier will trigger FIB update, so that
@@ -684,7 +684,8 @@ static void check_lifetime(struct work_struct *work)
         if (time_before(next_sched, now + ADDRCONF_TIMER_FUZZ_MAX))
                 next_sched = now + ADDRCONF_TIMER_FUZZ_MAX;
 
-        schedule_delayed_work(&check_lifetime_work, next_sched - now);
+        queue_delayed_work(system_power_efficient_wq, &check_lifetime_work,
+                        next_sched - now);
 }
 
 static void set_ifa_lifetime(struct in_ifaddr *ifa, __u32 valid_lft,
@@ -842,7 +843,8 @@ static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh)
                 ifa = ifa_existing;
                 set_ifa_lifetime(ifa, valid_lft, prefered_lft);
                 cancel_delayed_work(&check_lifetime_work);
-                schedule_delayed_work(&check_lifetime_work, 0);
+                queue_delayed_work(system_power_efficient_wq,
+                                &check_lifetime_work, 0);
                 rtmsg_ifa(RTM_NEWADDR, ifa, nlh, NETLINK_CB(skb).portid);
                 blocking_notifier_call_chain(&inetaddr_chain, NETDEV_UP, ifa);
         }
@@ -2322,7 +2324,7 @@ void __init devinet_init(void)
         register_gifconf(PF_INET, inet_gifconf);
         register_netdevice_notifier(&ip_netdev_notifier);
 
-        schedule_delayed_work(&check_lifetime_work, 0);
+        queue_delayed_work(system_power_efficient_wq, &check_lifetime_work, 0);
 
         rtnl_af_register(&inet_af_ops);