Re: [PATCH] slab: remove the SLUB_DEBUG functionality and config option

[Pedro Falcato]

On Wed, Apr 01, 2026 at 12:59:29PM +0200, Vlastimil Babka (SUSE) wrote:
> The boot-time enabled per-cache debugging has served us well in the
> past, but it's time for it to go, for the following reasons.
> 
> - It's a debugging feature. However, thanks to the advent of LLM-based
>   reviews, we are not adding bugs to the kernel anymore, so it's
>   unnecessary now.
> 
> - KASAN is more powerful anyway for the classes of bugs that SLUB_DEBUG
>   can catch. But I suspect KASAN is likely to be removed soon too, see
>   above.
> 
> - SLAB never had no such dynamic debugging functionality. With the
>   introduction of sheaves percpu caching, we have turned SLUB back into
>   SLAB partially, so this just follows that direction.
> 
> - It's removing ~2500 lines of code and I want to keep my overal
>   diffstats negative. This adds a nice margin.
> 
> Since the slub kunit test depends on SLUB_DEBUG, remove it too. It's not
> a big loss, see the first point above.

Did you check if there's a performance regression with this patch?

> 
> Singed-off-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>
> ---
> Signed-off-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>

LGTM, thanks

Signed-off-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>

-- 
Pedro