Title: Performance comparison between isoalloc 1.0.0 and 1.1.0
Date: 2021-12-22 22:00

[struct](https://github.com/struct) recently released the version [1.1.0](https://github.com/struct/isoalloc/releases/tag/1.1.0):
of [isoalloc](https://github.com/struct/isoalloc).

> This release brings many bug fixes and performance improvements from the last few months of development.
> The most noteworthy of which is the zone lookup table which has significantly improved the performance of both allocations and frees.

This is an excellent <s>excuse</s> opportunity to use [mimalloc-bench](https://github.com/daanx/mimalloc-bench),
to which I [contributed to recently](https://github.com/daanx/mimalloc-bench/commits?author=jvoisin),
to check the differences between the old and the new version of isoalloc in various benchmarks.

.              | 1.0.0 (in s)  | 1.1.0 (in s) | 1.0.0 (in KB) | 1.1.0 (in KB)
-------------- | ------------- | ------------ | --------------| ------------
cfrac          | 14.630        | 16.000       | 15316         | 15644
espresso       | 9.240         | 9.940        | 56944         | 56104
barnes         | 4.470         | 4.530        | 66100         | 66104
redis          | 15.986        | 16.231       | 70088         | 70620
larsonN        | 1176.977      | 1377.436     | 41804         | 45052
larsonN-sized  | 1176.868      | 1402.950     | 41884         | 44912
mstressN       | 0.200         | 0.210        | 51056         | 51292
rptestN        | 1.203         | 0.978        | 60232         | 58724
alloc-test1    | 10.240        | 11.280       | 35928         | 35600
alloc-testN    | 35.800        | 37.040       | 35972         | 35720
xmalloc-testN  | 72.864        | 66.890       | 38468         | 51480
cache-scratch1 | 2.430         | 2.150        | 11640         | 11544
cache-scratchN | 5.790         | 1.440        | 11476         | 11656
glibc-simple   | 12.260        | 13.510       | 14996         | 14908
glibc-thread   | 2433.354      | 2288.543     | 43480         | 43480
gs             | 223.630       | 231.570      | 304152        | 308712

The two first columns of data contain the time required to run the benchmark,
the two last ones are about the maximum [resident set size](https://en.wikipedia.org/wiki/Resident_set_size) of the process during its lifetime
in kilobytes.

The only significant improvement (x4) is on the `cache-scratchN` benchmark,
designed to stress-test cache contention and threading locking.
The rest is more of less in the noise level, except a small increase
in memory consumption on larsonN and larsonN-sized, but nothing crazy.
It's worth upgrading :P