Re: [PATCH] mm: Convert memory block states (MEM_*) macros to enum

[David Hildenbrand <david@redhat.com>]

> I read
> https://lore.kernel.org/all/809f552d-3282-4746-ba49-066d2bd8d44f@lucifer.local/
> ("it's not valid to have flag values as an enum") as a claim that this
> was invalid at the language level, but it sounds like your objection is
> more of a personal style preference. Which is totally fine, the MM
> subsystem can have whatever rules it wants.
> 
> To play devil's advocate, using a named enum for flags makes it easy to
> document what flags are used for a given field

A current best practice for flags is to use a __bitwise typedef. That 
way, sparse will be able to make sure that people are not using other 
random values.

We don't make use of that everywhere yet, of course. FOLL_ flags are 
still wrapped in an enum, for example.

-- 
Cheers

David / dhildenb