Re: [PATCH v2 3/6] mm/slab: Support disabling SLAB_BUCKETS at boot

[Harry Yoo <harry@kernel.org>]

A gentle ping to Kees to hear his thoughts on having a bit more
coarse grained boot parameter e.g.) `slab_hardening=` to specify
how much performance/memory is worth sacrificing for enhanced security.

Quoting an email from [1], Harry Yoo wrote:
> On Wed, Oct 28, 2026 at 11:27:37PM +0800, Chris Down wrote:
> > Harry Yoo writes:
> > > If we end up supporting boot-time parameters for hardening,
> > > I think it should be all enabled (or disabled) by:
> > > 
> > >  slab_hardening=none|light|full
> > >  # please feel free to suggest bertter names
> > > 
> > > none: "Turn of all of them to maximize performance"
> > > 
> > > light: "I'm willying to sacrifice _some_ memory and CPU for security"
> > > 
> > > full: "I'm willying to sacrifice more overhead for security
> > >
> > > IMHO more fine-grained knob for each feature doesn't make much sense.
> >
> > I think if we did the 4 knobs that is a good idea. Given now it's two, I
> > think it seems reasonable to keep it as two separate knobs unless you
> > object? Otherwise I think given it will only cover the latter two, it
> > should be something like kmalloc_isolation= instead. Let me know what you
> > think.
> 
> There has been constant, steady efforts to add more and more hardening
> features over the last decade. So I'd say slab_hardening= is more
> future proof :-)
> 
> Kees or Marco might have more insights on this.

[1] https://lore.kernel.org/linux-mm/auIVIKxjrdXIaUIY@thinkstation

-- 
Cheers,
Harry / Hyeonggon