Jason A. Donenfeld says:

====================
wireguard fixes for 5.13-rc5

Here are bug fixes to WireGuard for 5.13-rc5:

1-2,6) These are small, trivial tweaks to our test harness.

3) Linus thinks -O3 is still dangerous to enable. The code gen wasn't so
   much different with -O2 either.

4) We were accidentally calling synchronize_rcu instead of
   synchronize_net while holding the rtnl_lock, resulting in some rather
   large stalls that hit production machines.

5) Peer allocation was wasting literally hundreds of megabytes on real
   world deployments, due to oddly sized large objects not fitting
   nicely into a kmalloc slab.

7-9) We move from an insanely expensive O(n) algorithm to a fast O(1)
     algorithm, and cleanup a massive memory leak in the process, in
     which allowed ips churn would leave danging nodes hanging around
     without cleanup until the interface was removed. The O(1) algorithm
     eliminates packet stalls and high latency issues, in addition to
     bringing operations that took as much as 10 minutes down to less
     than a second.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>