sbrk(2) broken

Dag-Erling Smørgrav des at
Thu Jan 10 06:31:42 PST 2008

Dag-Erling Smørgrav <des at> writes:
> Peter Schuller <peter.schuller at> writes:
> > However, in this context it will likely only help partially since you still
> > need a full page to be free (and with a lot of programs many allocations will
> > be significantly smaller than that, and I have to assume no real-life malloc
> > will align all allocations to pages, or the overhead would be extreme).
> Page-aligning every allocation would be supremely stupid, and jemalloc
> does so only for allocations larger than a page.

I misread your "no" as "any", so it seems we are in violent agreement.

However, most allocators these days are zone or slab allocators (or
similar in principle), and are pretty good at minimizing external
fragmentation except for pathological cases, which are suprisingly rare
in practice.

Dag-Erling Smørgrav - des at

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