Re: [PATCH 1/6] prctl: introduce PR_THP_POLICY_DEFAULT_HUGE for the process

[David Hildenbrand <david@redhat.com>]

On 15.05.25 20:09, Liam R. Howlett wrote:
> * David Hildenbrand <david@redhat.com> [250515 13:30]:
>>>>
>>>
>>> Did we document all this? :)
>>>
>>> It'd be good to be super explicit about these sorts of 'dependency chains'.
>>>
>>
>> Documentation/admin-guide/mm/transhuge.rst has under "Global THP controls"
>> quite some stuff about all that, yes.
>>
>> The whole document needs an overhaul, to clarify on the whole terminology,
>> make it consistent, and better explain how the pagecache behaves etc. On my
>> todo list, but I'm afraid it will be a bit of work to get it right / please
>> most people.
> 
> Yes, the whole thing is making me grumpy (more than my default state).
> The more I think about it, the more I don't like the prctl approach
> either...
> 
> I more than dislike flags2... I hate it.
> 
> but no prctl, no cgroups, no bpf.. what is left?  A new policy groups
> thing?  No, not that either, please.
> 
> To state the obvious, none of this is transparent.

New to the "transparent" huge page world where not that much is 
"transparent"!?

It's completely in-transparent to most people how it works :D

Yeah, that's why I suggested to piggyback on VM_HUGEPAGE/VM_NOHUGEPAGE. 
Something we already have and that we will probably have for a long time 
... :)

-- 
Cheers,

David / dhildenb