Re: [PATCH] mm/slub: serve slabobj_ext array from a strictly larger kmalloc cache

[Harry Yoo]

On 6/30/26 4:52 AM, Shakeel Butt wrote:
> On Sun, Jun 28, 2026 at 09:28:51PM -0700, Suren Baghdasaryan wrote:
> > On Sun, Jun 28, 2026 at 8:57 PM Harry Yoo <harry@xxxxxxxxxx> wrote:
> > >
>
> [...]
>
> Thanks all for great discussion. Let me summarize the conclusion and please
> correct me if I missed something.

I think you didn't miss anything.
> Let's keep the original one-line fix (serve the obj_exts array from a
> strictly larger cache, making the relation a DAG).

Right.

> We will NOT gate it on> mem_alloc_profiling_enabled() as I floated 
earlier

Right.
> -- per Harry, is_kmalloc_normal(s) is already the right condition,

Right.

> and gating on> profiling would miss the SLUB_TINY + 
__GFP_RECLAIMABLE|__GFP_ACCOUNT memcg
> case.

Right.

> So the bump stays unconditional for is_kmalloc_normal() caches.

Right.

> This over-allocates the array for larger caches, but only for profiling and
> SLUB_TINY+MEMCG users (the latter unrealistic). Acceptable for a small,
> backportable fix.

Yes.

Thanks!

--
Cheers,
Harry / Hyeonggon