syslink effort update

Erik Wikström erik-wikstrom at
Fri Apr 27 10:47:02 PDT 2007

On 2007-04-27 04:38, Matthew Dillon wrote:

[snip some really cool stuff]

    The 64 bit sysids will be unique, which is a very simple mechanism...
    each cpu just initializes a 64 bit sysid to a shifted timestamp on
    boot, and then increments it by <ncpus> to 'allocate' a sysid.  You
    can't get much simpler then that.  I don't think it would be possible
    to overflow a 64 bit counter, even incrementing by ncpus, without at
    least a hundred years of uptime and I'm just not worried about a
    hundred years of uptime for a single host.
Since most of it is a bit above me I'll ask about what I can understand. 
While I agree with you that 64 will probably suffice I also know of 
someone who thought that 640k would be enough memory and another who 
though that the world would never need more than one super-computer. But 
if I understand things correctly it will be fairly easy to upgrade to 
128 (or whatever) bits in the future should that be necessary since the 
sysid is centralized to sysreg, the SYSLINK protocol and whatever uses 
it. So basically all it would take is a change of type in a few places 
and a recompile right?

Erik Wikström

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