Re: [PATCH slab/for-next-fixes v3 3/4] lib/alloc_tag: introduce mem_alloc_profiling_permanently_disabled()

[Harry Yoo <harry@kernel.org>]

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On 7/14/26 1:15 AM, Vlastimil Babka (SUSE) wrote:
> On 7/13/26 17:43, Suren Baghdasaryan wrote:
>> On Mon, Jul 13, 2026 at 7:29 AM Harry Yoo (Oracle) <harry@kernel.org> wrote:
>>>
>>> mem_alloc_profiling_enabled() tells whether memalloc profiling is
>>> currently enabled. However, even when this function returns false,
>>> it can be enabled later.
>>>
>>> However, this is not enough. Some optimizations can be applied only when
>>> memalloc profiling is permanently disabled. For example, to skip the
>>> creation of KMALLOC_NO_OBJ_EXT caches at boot time, mem_profiling must
>>> be set to "never", "0" w/ debugging on, or have been shutdown so that
>>> it can no longer be enabled.
>>>
>>> Introduce mem_alloc_profiling_permanently_disabled() for this purpose.
>>
>> nit: I would call it mem_alloc_profiling_supported() but this name would do.
> 
> I wouldn't like that name, because _supported to me sounds like those
> CONFIG_ARCH_SUPPORTS... things and not something that was just disabled.

Agreed!

Actually, last year I wasn't sure what "_support" in
mem_profiling_support means and had to look at the code while fixing a
bug [1].

This year I forgot what it meant and had to look at the code again :)

> I suggested mem_alloc_profiling_unavailable(), but it's not ideal either,

Hehe, in terms of 'the meaning is obvious without reading the code',
it's not very straightforward...

> naming is hard.

Agreed!

[1]
https://lore.kernel.org/linux-mm/20250624072513.84219-1-harry.yoo@oracle.com

-- 
Cheers,
Harry / Hyeonggon


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