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Re: Something is broken in repack
Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> writes:
> Hi,
>
>> Note that delta following involves patterns something like
>>
>> allocate (small) space for delta
>> for i in (1..depth) {
>> allocate large space for base
>> allocate large space for result
>> .. apply delta ..
>> free large space for base
>> free small space for delta
>> }
>>
>> so if you have some stupid heap algorithm that doesn't try to merge and
>> re-use free'd spaces very aggressively (because that takes CPU time!),
>
> ptmalloc2 (in glibc) _per arena_ is basically best-fit. This is the
> best known general strategy,
Uh what? Someone crank out his copy of "The Art of Computer
Programming", I think volume 1. Best fit is known (analyzed and proven
and documented decades ago) to be one of the worst strategies for memory
allocation. Exactly because it leads to huge fragmentation problems.
--
David Kastrup, Kriemhildstr. 15, 44793 Bochum