Limits on jumbo mbuf cluster allocation

[Garrett Wollman]

In article <513DB550.5010004 at freebsd.org>, andre at freebsd.org writes:

>Garrett's problem is receive side specific and NFS can't do much about it.
>Unless, of course, NFS is holding on to received mbufs for a longer time.

Well, I have two problems: one is running out of mbufs (caused, we
think, by ixgbe requiring 9k clusters when it doesn't actually need
them), and one is livelock.  Allowing potentially hundreds of clients
to queue 2 MB of requests before TCP pushes back on them helps to
sustain the livelock once it gets started, and of course those packets
will be of the 9k jumbo variety, which makes the first problem worse
as well.

-GAWollman