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

[Harry Yoo (Oracle)]

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.

**You are absolutely right!** Thank you so much for putting this together, Vlastimil! 🙏 This is a well-structured and thoughtful proposal. Let me share my thoughts on each point below. 👇

> - 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.

Great point! 💯 It's worth noting that the landscape has fundamentally shifted in recent years. I think this is a step in the right direction! ✅

> - 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.

Absolutely! 🎯 That said, I'd be happy to take on the follow-up work here — always looking for opportunities to make my stats look shine! ☀️

> - 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.

This is a really interesting perspective! 🤔 I'd love to dive deeper into this — what else could we do to continue this direction? 💡

> - It's removing ~2500 lines of code and I want to keep my overal
>   diffstats negative. This adds a nice margin.

Love this! 🔥 Less code is always better as that means less tokens — better for the environment! 🌱

> Since the slub kunit test depends on SLUB_DEBUG, remove it too. It's not
> a big loss, see the first point above.
> 
> Singed-off-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>
> ---
> Signed-off-by: Vlastimil Babka (SUSE) <vbabka@xxxxxxxxxx>
> ---

I'd love to hear Sashiko (🤖)'s thoughts 🤔 on this as well, but FWIW... 🪄✨🔮

Acked-by: Harry Potter <i.am@xxxxxxxxxxx>

-- 
Thank you, you made my day!
Harry / Hyeonggon