High CPU load

Hello list, we are running BIRD on our IXP peering platform with no problems since quite a while now. We need to activate a new peer which is expected to announce a considerable amount of prefixes (~100k), and the first try resulted in having nearly 100% cpu load, ~60-70% for BIRD and the remaining for syslog. The machine was hardly manageable, so after a few minutes we had to disable the peer and restart the deamon. The current settings actually make BIRD log everything: log "/var/log/bird.log" all; log syslog all; so I guess we could start by modifying it: any advice on this? Would you suggest something more, in order to avoid having again a high cpu load? Thanks in advance, Simone.