Persistence VM?

Stephen Pair spair at acm.org
Mon Aug 19 20:09:04 UTC 2002


> Unless my math is as bad as my implementation of #removeAll:, 
> with one extra word for each non-compact header, that makes a total of
> 	(100 - 20.43) / 100 * 415298 * 4 / 1024 = 1290 kilobytes
> saved by using compact headers.
> 
> Or, to put it another way, about 7% of the total size of the 
> image (17698 kilobytes).
> 
> Ian

Sounds correct to me, but you meant "with one extra word for each
compact header" instead of "with one extra word for each non-compact
header" correct?

Also, even if the cci not zero, isn't it possible for that object to be
larger than 255 bytes (thus requiring a three word header even though
it's a compact class)?  If so, then even 7% is a tad (but just a tad)
high.

- Stephen




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