Does FreeBSD have sendmmsg or recvmmsg system calls?

[Robert Watson]

On Sun, 3 Jan 2016, Rui Paulo wrote:

>> NetBSD 7.0 has just introduced these two syscalls. And Linux also has them.
>> 
>> Does FreeBSD have them? Or plan to support them in the future?
>
> FreeBSD does not have them.  It doesn't seem especially hard to implement, 
> though.  Do you know any major application already using them?

I see no harm in having the system calls.  When I chatted with the authors of 
nsd a couple of years ago (they had originally promoted the approach), they 
told me they felt it only offered incremental benefit and didn't particularly 
recommend that FreeBSD adopt it.  However, it would undoubtably see use and 
does offer some opportunities for future batching-related performance 
operations, so if someone wants to pursue introducing it, do go ahead.  Or 
just introduce a libc implementation that can be converted to a kernel 
implementation later if that is determined to be beneficial.  But the nsd 
observations don't (currently) lead me to believe that it is critical to do 
so.

Robert