net: add a route cache full diagnostic message

In some testing scenarios, dst/route cache can fill up so quickly
that even an explicit GC call occasionally fails to clean it up. This leads
to sporadically failing calls to dst_alloc and "network unreachable" errors
to the user, which is confusing.

This patch adds a diagnostic message to make the cause of the failure
easier to determine.

Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Peter Oskolkov 2019-01-16 08:50:28 -08:00 committed by David S. Miller
parent 68d7431553
commit 22c2ad616b
1 changed files with 5 additions and 1 deletions

View File

@ -98,8 +98,12 @@ 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(ops))
if (ops->gc(ops)) {
printk_ratelimited(KERN_NOTICE "Route cache is full: "
"consider increasing sysctl "
"net.ipv[4|6].route.max_size.\n");
return NULL;
}
}
dst = kmem_cache_alloc(ops->kmem_cachep, GFP_ATOMIC);