Re: Chelsio cards, jumbo frames, memory fragmentation and performance in FreeBSD 13.x?

From: Ryan Stone <>
Date: Fri, 03 Dec 2021 21:17:49 UTC
Set it to 4k and move on.  I'm not aware of any efforts in the VM
layer or network stack to make >PAGE_SIZE clusters usable in practical
situations.  Honestly, at this point I wish that we'd just kill them

On Fri, Dec 3, 2021 at 12:52 PM John Jasen <> wrote:
> Pretty close to two years ago, we tripped across conditions where heavily
> used FreeBSD 11.x packet-filter firewalls would slow to a crawl and load
> would go crazy.
> In a fit of hopefulness with our upgrade to FreeBSD 13.0, I removed the
> hw.cxgbe.largest_rx_cluster settings we put in place -- only to have our
> hardest hit firewall experience high load and plummeting bandwidth within a
> few hours.
> So, I have two questions -- is there a better fix for this? Or, is the
> approach to set largest_rx_cluster to 4k and move on?
> Thanks in advance!