Re: UDP buffer sizes

[janicetr%posteo.de@localhost]

On 2020-03-10 14:20, Greg Troxel wrote:
> So two thoughts:
> increase nmbclusters

sysctl kern.mbuf.nmbclusters
kern.mbuf.nmbclusters = 131055

sysctl -w kern.mbuf.nmbclusters=262144
kern.mbuf.nmbclusters: 131055 -> 262144
ifconfig: status: getsock: No buffer space available

sysctl -w kern.mbuf.nmbclusters=524288
sysctl: kern.mbuf.nmbclusters: Invalid argument

Maybe I hit a hard limit?

> To work on the second approach, I'd use ktrace to see the failing
> syscall.  And then find the code that handles the ioctl.   I looked in
> src/sys/netinet/udp_usrreq.c  and am beginning to think per-udp socket
> buffer sizes aren't supported, which seems surprising.

494 1 ifconfig CALL __socket30(2,2,0)
494 1 ifconfig RET __socket30 -1 errno 55 No buffer space available

Best regards:

J.