ten thousand small processes

Terry Lambert tlambert2 at mindspring.com
Fri Jun 27 04:41:54 PDT 2003

"D. J. Bernstein" wrote:
> Bakul Shah writes:
> > Instead of complaining about wasting 78 megabytes and arguing
> > about why various proposed solutions fall short and why your
> > way is the best, why don't you come up with a patch that
> > saves space for small programs?
> Funny. Seems to me that I keep making concrete suggestions---including a
> detailed proposal for giving more space to malloc()---and the answer is
> consistently ``We really don't care about per-process overhead.'' What's
> the benefit of a patch for people who don't even see the problem?

Your "concrete proposal for malloc" made a number of bad

o	"UVA == 4G", rather than "UVA + KVA == 4G"

	Costs to move to "UVA == 4G":

	o	pages must be mapped before each copy of
		data across a protection domain
	o	pages must be unmapped afterwards

o	If we had access to another 2G of UVA, we'd have no
	better use for it than to make malloc more space

My answer, at least, was "too computationally expensive for a
general purpose OS when making the size/computational overhead

-- Terry

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