net/dst: use a smaller percpu_counter batch for dst entries accounting
percpu_counter_add() uses a default batch size which is quite big
on platforms with 256 cpus. (2*256 -> 512)
This means dst_entries_get_fast() can be off by +/- 2*(nr_cpus^2)
(131072 on servers with 256 cpus)
Reduce the batch size to something more reasonable, and
add logic to ip6_dst_gc() to call dst_entries_get_slow()
before calling the _very_ expensive fib6_run_gc() function.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/core/dst.c b/net/core/dst.c
index 193af52..d6b6ced 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -81,11 +81,11 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
{
struct dst_entry *dst;
- if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) {
+ if (ops->gc &&
+ !(flags & DST_NOCOUNT) &&
+ dst_entries_get_fast(ops) > ops->gc_thresh) {
if (ops->gc(ops)) {
- printk_ratelimited(KERN_NOTICE "Route cache is full: "
- "consider increasing sysctl "
- "net.ipv[4|6].route.max_size.\n");
+ pr_notice_ratelimited("Route cache is full: consider increasing sysctl net.ipv6.route.max_size.\n");
return NULL;
}
}