Re: [PATCH v3] mm/mempool: Untangle CONFIG_SLUB_DEBUG_ON abuse and switch to static key

[SeongJae Park <sj@kernel.org>]

On Thu, 4 Jun 2026 19:03:18 +0800 lirongqing <lirongqing@baidu.com> wrote:

> From: Li RongQing <lirongqing@baidu.com>
> 
> The mempool subsystem historically wrapped its debugging logic inside an
> merely defines compile-time defaults for SLUB and caused two flaws:
> 
> 1. On production kernels where CONFIG_SLUB_DEBUG=y but
>    CONFIG_SLUB_DEBUG_ON=n, mempool debugging was completely compiled out
>    at compile time.
> 2. On kernels with CONFIG_SLUB_DEBUG_ON=y, mempool debugging stayed active
>    even if a user explicitly disabled slub debugging at boot time.
> 
> Clean up this mess by removing the #ifdef and switching to a runtime static
> key (mempool_debug_enabled), allowing mempool debugging to be toggled
> cleanly via its own boot parameter.

Makes sense to me.

> 
> Suggested-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> Cc: Vlastimil Babka <vbabka@kernel.org>
> Cc: Harry Yoo <harry@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Hao Li <hao.li@linux.dev>
> Cc: Christoph Lameter <cl@gentwo.org>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Roman Gushchin <roman.gushchin@linux.dev>
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: Usama Arif <usama.arif@linux.dev>

Reviewed-by: SeongJae Park <sj@kernel.org>


Thanks,
SJ

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