DragonFly now supports running on up to 256 CPUs. 256 is the initial limit on the basic interrupt controller, and it can be extended further. It’s been tested on 255 CPUs so far, since that’s the highest number of CPUs you can bring up in qemu.
A running description of activity related to DragonFly BSD.
Well, the question now is if there are machines that have like 256+ CPUs on one board.
And if that could be then tested on real hardware. Of course, one can not expect DragonFlyBSD could afford that kind of money, so one would need someone who has such thing to test it then.
No idea … the biggest I know about is that iXsystems FreeBSD one.
Just a FYI:
http://lists.gnu.org/archive/html/qemu-stable/2014-05/msg00037.html
“Change MAX_CPUMASK_BITS from 255 to 4096”