A look at The Machine [LWN.net]

A look at The Machine

Posted Aug 30, 2015 22:54 UTC (Sun) by keithp (subscriber, #5140)
In reply to: A look at The Machine by mathstuf
Parent article: A look at The Machine

At least limited virtual address space is cheaper to hack around than limited physical address space. Swapping virtual to physical mappings is something the cache system understands, while swapping physical to device mappings makes the cache system very unhappy.

Just give us enough bits to address every particle in the universe and we'll be happy, right?

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A look at The Machine

Posted Aug 30, 2015 23:15 UTC (Sun) by mathstuf (subscriber, #69389) [Link]

Well, with pointers being distinct entities from an integer representation, I imagine one could spec a Mill processor with 128 bit pointers so you'd have 124 (or 120 to expand the GC bits some) bits of address.

Looking back at the slides[1], it appears that there is virtual memory addressing, but there is only one address space. This allows them to put the TLB behind the cache (slide 52). Not sure if that would change things for The Machine.

[1]http://millcomputing.com/docs/memory/