[REF] Memory Allocator Benchmark

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This one will be of more interest to kernel developers.

Link to Spreadsheet: Results

RcrdBrt asked me to see which memory allocator performed best, and provided me with four identical kernels except for the allocators being SLQB, SLAB, SLUB, and SLOB.

SLUB turns out to have a slight performance advantage, as RcrdBrt had suspected.

The rank was:
SLUB - 980.56
SLQB - 972.17
SLAB - 967.72
SLOB - 967.72

Not much difference really, but every little helps, as they say at Tesco (Britain's leading super market/Religion).

Thanks to RcrdBrt for trusting me with this nice little study, and to Chainfire for the very useful benchmarking app. (See here)

Methodology

Technical detail (it's not necessary to read this!)

I used CF-Bench to obtain values for:
Native MALLOCS
Native Mem Read
Native Mem Write
Java Mem Read
Java Mem Write

...and used statistical methods to boil 10 passes for each allocator down to one final score: 10 passes is enough to get the mean and median within one percent of each other, i.e. establishes a confidence in the mean, assuming normally distributed data. Three standard deviations are subtracted from the mean, to show the minimum score we'd expect 99.7% of results to be above. This is to penalize variability (high peaks are less significant than a good consistency). The geometric mean is taken of the five end results to provide one final score.

Bedalus can't live without benchmarks. Closed UX benchmark yesterday and opened a new one today
One more instructive and helpful benchmark buddy

Most kernel developers prefer using SLQB. Any thoughts on why this is the case? Do they have a special reason for that or just a matter of not knowing better? Cheers!

RcrdBrt said it was the fashion! Tbh i don't know the differences between them, but some casual googling showed that slub has had success in other Linux arenas

Originally Posted by apatal

Most kernel developers prefer using SLQB. Any thoughts on why this is the case? Do they have a special reason for that or just a matter of not knowing better? Cheers!

Buzzwordism. The other 3 are in kernel.

Sent from my Nexus Prime.

Originally Posted by morfic

Buzzwordism. The other 3 are in kernel.

You mean all those allocators are present but they mention only SLQB because it's the trend?

Sent from my Nexus S

Originally Posted by apatal

You mean all those allocators are present but they mention only SLQB because it's the trend?

Sent from my Nexus S

Correct.

Sent from my Nexus Prime.

Man, bedalus is really fast!

@morfic:
So, in the ICS stock 3.0.8 kernel, how many and which allocators are present?
Am I correct to say that all those four allocators are present, but only one is used?
Sorry for these dumb questions.

Originally Posted by glennkaonang

Man, bedalus is really fast!

@morfic:
So, in the ICS stock 3.0.8 kernel, how many and which allocators are present?
Am I correct to say that all those four allocators are present, but only one is used?

SLAB, SLUB, SLOB are in most (mainline) Linux Kernel, SLQB is patched in.

bedalus, did you run this on GB too?