Bump default MBUF's?



  • With the increase in usage of multicore processors like the C2758, is it worth bumping the default MBUF value for 2.3? I always have to nudge it up slightly on clean installs and recall seeing quite a few threads from new users on this point.



  • I would also really like this


  • Rebel Alliance Developer Netgate

    The problem is that it is very hardware-dependent and some hardware requires it be set in loader.conf before the NICs are initialized so we can't detect the hardware and then tune it.

    For hardware we sell, since we know the hardware, we pre-fill that and other things with better defaults but for general use it requires manual tuning by someone familiar with the hardware (read: you)

    It can be adjusted after boot by using a tunable, but that has a couple problems as well: Mostly that it's too late for some hardware, and also can be lost if an old config is restored, plus if it's too high it can run the system out of kernel memory.

    So any auto-tuning would not be trivial having to take quite a lot of factors into account: amount of RAM, kmem, NICs types/drivers/queues, etc, etc, etc.

    It's likely far too late for anything of that nature to make it into 2.3.


  • Netgate

    It's unlikely that we'll ever do this for the community version of pfSense (though one can hold out hope that FreeBSD auto-tunes this type of thing someday.)

    As JimP mentions, for the hardware that we sell (where we understand all of the characteristics, we can ship with tuned settings.


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