Using the new bridges of FreeBSD 15(blog.feld.me)

63 pointsby vermaden6 hours ago5 comments

j16sdiz2 hours ago
Why sudden surge of FreeBSD-related posts?
Did anything special or new happened on FreeBSD land?
- kev0092 hours ago
  15.0 was released a couple months ago, hence the title.
  - j16sdiz2 hours ago
    We have three (including this) FreeBSD posts in the past two days.
    Back to FreeBSD: Part 1 (hypha.pub) https://news.ycombinator.com/item?id=47108989
    Linuxulator on FreeBSD Feels Like Magic (hayzam.com) https://news.ycombinator.com/item?id=47113527
    kev0092 hours ago
    Generally people get more excited any time a major release of anything comes out. But FWIW HN has always had favorable front paging for anything related to FreeBSD and OpenBSD.
    unethical_ban23 minutes ago
    No conspiracy, I think it just happens. One person posts something, maybe someone else reads it and gets into a rabbit hole on a topic, or maybe someone sees an opportunity to throw more conversation pieces at something hot.
ggm5 hours ago
When this settles down, I look forward to all of jail/iojail, Sylve, Bastille, Bhyve documenting this in a mutually consistent manner. As it stands, I have managed to completely knot my brain over the abstractions, what is happening. It's me, not the systems, but I think there is a little bit of "meh, I understand it, so it must be obvious to anyone smart" going on, and alas, I am not smart, and I get confused easily.
I'm in bastille atm, but have been in all of them and TrueNAS core. and libvirt over on the other unix.
- _0xdd22 minutes ago
  Honestly, best thing I did was ditch all that and just read the handbook, specificially chapter 17 [1]. All of my jails are now set up manually, initially using /etc/jail.conf, and now individual jail configs in /etc/jail.conf.d/.
  I still use vm-bhyve [2] for my Bhyve virtual machines, but that's been rock solid for me for years.
  [1] https://docs.freebsd.org/en/books/handbook/jails/
  [2] https://github.com/freebsd/vm-bhyve
shashasha25 hours ago
Bhyve bridges are inefficient: every packet traverses NIC → CPU → bridge → VM, adding unnecessary copies that kill throughput. Switching to SR-IOV eliminated that overhead and I saturated the 10 GbE link.
- Veserv4 hours ago
  I do not see how that follows. Memory bandwidth is measured in the hundreds of Gb/s. You can issue tens of unnecessary full memory copies before you bottleneck at a paltry 10 Gb/s.
  It is much more likely there is something else terribly wrong in a network stack if it can not even drive a measly 10 Gb/s.
  - stingraycharles4 hours ago
    That assumes memory bandwidth is the issue, and not latency and/or CPU.
- kev0092 hours ago
  It would benefit from a batching mechanism.
- assimpleaspossi5 hours ago
  You used the new optimized bridges on FreeBSD 15?
- gigatexal5 hours ago
  On Linux?
waynesonfire4 hours ago
> -tso4 -tso6 -vlanhwfilter -vlanmtu -vlanhwtso -vlanhwtag -vlanhwcsum -lro
Whys the author disabling tso and lro? Whats the motivation?
I'm not familiar with the other flags.
- kev0092 hours ago
  People found this worked in the past and it gets copied around. There is no reason to disable some of this. Bridge will automatically disable LRO and find the common set of other offloads. TSO is not useful for a bridged guest.
- j16sdiz2 hours ago
  Looks like TSO does not support VLAN. Not sure about lro.
bzmrgonz3 hours ago
I for one welcome and applaud any progress on the bsd front,and this seems to be huge.