Re: mips64 on port-cobalt

["Alex Pelts" <alexp%broadcom.com@localhost>]

Not that this should stop anyone from trying, but I am not sure Qube
will gain anything by going 64 bit. While RM5231 processor is certainly
64bit, the system interface is 32bit so for every data memory read and
write it will require 2 accesses in 64 bit mode. Also data cache will be
effectively cut in half if most of the structure size would double due
to going to 64 bit.
Even all of this is mediated somehow, context switch will become 2x
slower due to doubling amount of data that needs to be saved and restored.
So aside from satisfying curiosity the 64bit mode will be detrimental to
Qube performance. And this thing already is not a speed daemon. Plus
this system can't physically accommodate enough memory to need 64 bits.

Regards,
Alex