Re: [PATCH 0/8] mm/slab: Support selecting slab hardening features at boot

[Harry Yoo]

On Tue, Oct 27, 2026 at 08:10:40AM +0100, Vlastimil Babka (SUSE) wrote:
> These two should be only a small cpu overhead, which is why distros
> generally enable them [1].

Yeah I'd expect the impact on them to be small enough.

> >   slab_buckets=
> >   kmalloc_partition=
> 
> These are more valid as there's a memory overhead tradeoff.

quickly measuring it on a VM with 64 CPUs and 64 GiB RAM:

w/ partitioned kmalloc: 94.0 MiB (235 kmalloc caches)
w/o partitioned kmalloc: 76.1 MiB (~17.9 MiB diff) (40 kmalloc caches) 

Mostly due to a large number number of under-utilized slabs after boot.
(per memalloc profiling)

slab_buckets had relately smaller impact, about ~1MiB after boot.

(Of course this is just after boot, and actual bloat depends on memory
 usage and fragmentation on production)

-- 
Cheers,
Harry / Hyeonggon