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 --- Initial support for power-efficient workqueues was added here: https://lkml.org/lkml/2013/4/24/215
net/ipv4/devinet.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 646023b..ac2dff3 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);