Comments
Patch
@@ -26,6 +26,11 @@ route/max_size - INTEGER
Maximum number of routes allowed in the kernel. Increase
this when using large numbers of interfaces and/or routes.
+neigh/default/gc_thresh1 - INTEGER
+ Minimum number of entries to keep. Garbage collector will not
+ purge entries if there are fewer than this number.
+ Default: 256
+
neigh/default/gc_thresh3 - INTEGER
Maximum number of neighbor entries allowed. Increase this
when using large numbers of interfaces and when communicating
@@ -778,6 +778,9 @@ static void neigh_periodic_work(struct work_struct *work)
nht = rcu_dereference_protected(tbl->nht,
lockdep_is_held(&tbl->lock));
+ if (atomic_read(&tbl->entries) < tbl->gc_thresh1)
+ goto out;
+
/*
* periodically recompute ReachableTime from random function
*/
@@ -832,6 +835,7 @@ next_elt:
nht = rcu_dereference_protected(tbl->nht,
lockdep_is_held(&tbl->lock));
}
+out:
/* Cycle through all hash buckets every base_reachable_time/2 ticks.
* ARP entry timeouts range from 1/2 base_reachable_time to 3/2
* base_reachable_time.
Since we have removed NCE (Neighbour Cache Entry) reference from routing entries, the only refcnt holders of an NCE are timer (if run) and the entry's owner table. As a result, neigh_periodic_timer() purges NCEs over and over even for gateways. It does not make sense to purge NCEs even if number of them is very small. The number of entries can be specified by gc_thresh1. Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> --- Documentation/networking/ip-sysctl.txt | 5 +++++ net/core/neighbour.c | 4 ++++ 2 files changed, 9 insertions(+)