Re: SLUB vs SLAB allocator with respect to 3.x and 4.x kernels

From: Austin S Hemmelgarn
Date: Thu Aug 27 2015 - 15:44:14 EST


On 2015-08-27 10:26, Navin Parakkal wrote:
Hi,

I found that in many worst case scenarios like fragmention of
allocator , slub performs well than slab.
I also noticed that Centos /Ubuntu etc switched to SLUB but SLES
still uses SLAB in the default image.

Any particular reason where SLAB is the choice ?


I ask this since i find SLUB to be the default choice since 2.6.23 as
per https://en.wikipedia.org/wiki/SLUB_(software)

IIRC, SLUB isn't available/reliable on some arches (that and in some setups, the worst case scenarios are likely to never happen (for example, a machine with 1T of RAM that get's rebooted daily isn't likely to have significant issues with memory fragmentation)).

SLES probably hasn't switched because they're an enterprise distro, which in turn means changing as little as possible when updating.


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