diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 36ebb4ad8a0a..7d7d4b17c0f0 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -99,6 +99,10 @@ #define INFINITY_LIFE_TIME 0xFFFFFFFF #define TIME_DELTA(a, b) ((unsigned long)((long)(a) - (long)(b))) +#define ADDRCONF_TIMER_FUZZ_MINUS (HZ > 50 ? HZ/50 : 1) +#define ADDRCONF_TIMER_FUZZ (HZ / 4) +#define ADDRCONF_TIMER_FUZZ_MAX (HZ) + #ifdef CONFIG_SYSCTL static void addrconf_sysctl_register(struct inet6_dev *idev); static void addrconf_sysctl_unregister(struct inet6_dev *idev); @@ -3107,15 +3111,15 @@ int ipv6_chk_home_addr(struct net *net, struct in6_addr *addr) static void addrconf_verify(unsigned long foo) { + unsigned long now, next, next_sec, next_sched; struct inet6_ifaddr *ifp; struct hlist_node *node; - unsigned long now, next; int i; rcu_read_lock_bh(); spin_lock(&addrconf_verify_lock); now = jiffies; - next = now + ADDR_CHECK_FREQUENCY; + next = round_jiffies_up(now + ADDR_CHECK_FREQUENCY); del_timer(&addr_chk_timer); @@ -3129,7 +3133,8 @@ static void addrconf_verify(unsigned long foo) continue; spin_lock(&ifp->lock); - age = (now - ifp->tstamp) / HZ; + /* We try to batch several events at once. */ + age = (now - ifp->tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ; if (ifp->valid_lft != INFINITY_LIFE_TIME && age >= ifp->valid_lft) { @@ -3199,7 +3204,21 @@ static void addrconf_verify(unsigned long foo) } } - addr_chk_timer.expires = time_before(next, jiffies + HZ) ? jiffies + HZ : next; + next_sec = round_jiffies_up(next); + next_sched = next; + + /* If rounded timeout is accurate enough, accept it. */ + if (time_before(next_sec, next + ADDRCONF_TIMER_FUZZ)) + next_sched = next_sec; + + /* And minimum interval is ADDRCONF_TIMER_FUZZ_MAX. */ + if (time_before(next_sched, jiffies + ADDRCONF_TIMER_FUZZ_MAX)) + next_sched = jiffies + ADDRCONF_TIMER_FUZZ_MAX; + + ADBG((KERN_DEBUG "now = %lu, schedule = %lu, rounded schedule = %lu => %lu\n", + now, next, next_sec, next_sched)); + + addr_chk_timer.expires = next_sched; add_timer(&addr_chk_timer); spin_unlock(&addrconf_verify_lock); rcu_read_unlock_bh();