SMP performance on drgonfly

Matthew Dillon dillon at
Fri May 18 16:50:51 PDT 2007

    A large chunk of the kernel still runs under the big giant
    lock, including the light weight processes that libthread_xu
    uses, so something like mysql is going to hit a lot of BGL

    You may be able to get DragonFly to run on the machines you
    were having problems with by compiling it with SMP but 
    without APIC_IO.  With that combination DragonFly will use
    the PIC in SMP mode, which usually works.

    I'd use 1.8 for any testing, or 1.9 Preview.  A lot of
    dangerous stuff is going into 1.9 HEAD right now (in particular,
    moving to a pluggable MBR/disklabel architecture so we can support
    64 bit disklabels and GPT and such.


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