Commit 19e16d22 authored by Hangbin Liu's avatar Hangbin Liu Committed by David S. Miller
Browse files

neigh: support smaller retrans_time settting 



Currently, we limited the retrans_time to be greater than HZ/2. i.e.
setting retrans_time less than 500ms will not work. This makes the user
unable to achieve a more accurate control for bonding arp fast failover.

Update the sanity check to HZ/100, which is 10ms, to let users have more
ability on the retrans_time control.

v3: sync the behavior with IPv6 and update all the timer handler
v2: use HZ instead of hard code number

Signed-off-by: default avatarHangbin Liu <liuhangbin@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 64948427

net/core/neighbour.c

+6 −4
Original line number Diff line number Diff line
@@ -1065,11 +1065,12 @@ static void neigh_timer_handler(struct timer_list *t) 
			neigh->updated = jiffies;

			atomic_set(&neigh->probes, 0);

			notify = 1;

			next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);

			next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),

					 HZ/100);

		}

	} else {

		/* NUD_PROBE|NUD_INCOMPLETE */

		next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);

		next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME), HZ/100);

	}



	if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&
@@ -1125,7 +1126,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 
			neigh->nud_state     = NUD_INCOMPLETE;

			neigh->updated = now;

			next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),

					 HZ/2);

					 HZ/100);

			neigh_add_timer(neigh, next);

			immediate_probe = true;

		} else {
@@ -1427,7 +1428,8 @@ void __neigh_set_probe_once(struct neighbour *neigh) 
	neigh->nud_state = NUD_INCOMPLETE;

	atomic_set(&neigh->probes, neigh_max_probes(neigh));

	neigh_add_timer(neigh,

			jiffies + NEIGH_VAR(neigh->parms, RETRANS_TIME));

			jiffies + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),

				      HZ/100));

}

EXPORT_SYMBOL(__neigh_set_probe_once);

net/ipv6/addrconf.c

+4 −3
Original line number Diff line number Diff line
@@ -1357,7 +1357,7 @@ retry: 


	regen_advance = idev->cnf.regen_max_retry *

			idev->cnf.dad_transmits *

			NEIGH_VAR(idev->nd_parms, RETRANS_TIME) / HZ;

			max(NEIGH_VAR(idev->nd_parms, RETRANS_TIME), HZ/100) / HZ;



	/* recalculate max_desync_factor each time and update

	 * idev->desync_factor if it's larger
@@ -4121,7 +4121,8 @@ static void addrconf_dad_work(struct work_struct *w) 


	ifp->dad_probes--;

	addrconf_mod_dad_work(ifp,

			      NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME));

			      max(NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME),

				  HZ/100));

	spin_unlock(&ifp->lock);

	write_unlock_bh(&idev->lock);
@@ -4527,7 +4528,7 @@ restart: 
				   !(ifp->flags&IFA_F_TENTATIVE)) {

				unsigned long regen_advance = ifp->idev->cnf.regen_max_retry *

					ifp->idev->cnf.dad_transmits *

					NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME) / HZ;

					max(NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME), HZ/100) / HZ;



				if (age >= ifp->prefered_lft - regen_advance) {

					struct inet6_ifaddr *ifpub = ifp->ifpub;

net/ipv6/ndisc.c

+2 −2
Original line number Diff line number Diff line
@@ -1359,8 +1359,8 @@ skip_defrtr: 


		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {

			rtime = (rtime*HZ)/1000;

			if (rtime < HZ/10)

				rtime = HZ/10;

			if (rtime < HZ/100)

				rtime = HZ/100;

			NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);

			in6_dev->tstamp = jiffies;

			send_ifinfo_notify = true;

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