in_broadcast() called for almost every packet in ip_output()

Ryan Stone rysto32 at
Wed Jul 20 19:50:07 UTC 2016

On Wed, Jul 20, 2016 at 3:22 PM, Andrew Gallatin <gallatin at>

> Caching sounds reasonable, but.. won't the lock still add overhead
> to paths like unconnected udp and packet forwarding?

Forwarded packets will never be broadcast, so checking for a broadcast
address would just be redundant.  Unconnected UDP would get overhead, but
I'm honestly not sure how many people care about the performance of
unconnected UDP.

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