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From: Jon Masters <jonathan@jonmasters.org>
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On 07/17/2012 05:50 AM, Alan Cox wrote:
>> Right, I would say that with any CPU core more powerful than this one
>> or with more than a few of these, you will also have trouble coming
>> up with workloads that really require the CPU performance but don't
>> also require a 64 bit virtual address space in either user space
>> or kernel.
> 
> There are lots of them - soft radio for example can burn near infinite
> CPU resource depending upon the amount you are fishing out, but its pure
> throughput.

I think A15 is likely to be a good 32-bit story there. Performance wise,
it's awesome. The reason for 64-bit is both emotional ("real servers
must be 64-bit! <pound the table and yell>"), and as an opportunity to
clean up lots of assumptions and have a standard base, but it's not the
end of the 32-bit story. I believe ARM have said many times that they're
not giving up on AArch32, and in fact, if you read the public ISA docs
you'll see additional 32-bit instructions in v8.

Jon.