net.bpf.zero_copy changed?

Emre Gundogan emre at
Thu Sep 3 02:35:31 UTC 2015

Hello there. I have recently upgraded a machine (amd64) running
10.2-STABLE (r286771) to revision r287298. After that I could no longer
run tcpdump on the interfaces (fails with 'pcap_loop: BIOCROTZBUF:
Capabilities insufficient'), or neither could I use pflogd (eats cpu)
unless I set sysctl net.bpf.zero_copy=0. Had that set to '1' earlier,
and everything was fine. Something changed recently?

Thanks a lot,

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