Using the new bridges of FreeBSD 15

(blog.feld.me)

85 points | by vermaden 10 hours ago ago

22 comments

  • j16sdiz 6 hours ago ago

    Why sudden surge of FreeBSD-related posts?

    Did anything special or new happened on FreeBSD land?

    • g0ran 28 minutes ago ago

      I think people are looking for new alternatives to tinker with. Linux is becoming new Windows and BSDs new Linux. I dunno what is Windows becoming, but it ain't good.

    • kev009 6 hours ago ago

      15.0 was released a couple months ago, hence the title.

      • j16sdiz 6 hours ago 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

        • kev009 6 hours ago 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.

          • shevy-java 2 hours ago ago

            Not disagreeing, but if the release was a few months ago, then the poster is quite correct - there is a recent "surge" of FreeBSD related posts. And these are not quite ... how shall I word it somewhat nicely ... not quite as fascinating to, say, a wider linux community as such. With that I don't mean "because we use linux, we are snobs", but that what the FreeBSD guys talk about, seems a little bit ... outdated. The heavy use of shell scripts for instance in this post here - I never understood that focus on shell scripts in general, including on Linux. I transitioned into using ruby (or python, but mostly ruby) to replace all shell script needs a long time ago. Every time I am assumed to have to write a shell script I wonder why I would want to cripple myself when I can use a better programming language instead. Many of these shown "innovations" are also not really groundbreaking. To me it seems as if there is a distinct lack of FreeBSD users out there compared to Linux users. As a consequence Linux simply has a lot more information and news (a lot of which is also low quality of course; I am not saying it is all pancakes and sunflowers in the Linux ecosystem either).

        • unethical_ban 5 hours ago 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.

    • shevy-java 2 hours ago ago

      I was wondering the same.

  • ggm 9 hours ago 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.

    • _0xdd 5 hours ago 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

  • shashasha2 10 hours ago 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.

    • Veserv 9 hours ago 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.

      • stingraycharles 9 hours ago ago

        That assumes memory bandwidth is the issue, and not latency and/or CPU.

    • kev009 6 hours ago ago

      It would benefit from a batching mechanism.

    • assimpleaspossi 10 hours ago ago

      You used the new optimized bridges on FreeBSD 15?

      • crest 4 hours ago ago

        The bridge driver gained features (vlan filtering) not performance.

    • gigatexal 9 hours ago ago

      On Linux?

  • waynesonfire 8 hours ago 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.

    • kev009 6 hours ago 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.

    • j16sdiz 6 hours ago ago

      Looks like TSO does not support VLAN. Not sure about lro.

    • crest 4 hours ago ago

      LRO because the bridge has to forward the real frames. TSO because it’s fairly useless now.

  • bzmrgonz 8 hours ago ago

    I for one welcome and applaud any progress on the bsd front,and this seems to be huge.