Re: [PATCH v2 1/2] mm: Move page struct poisoning to CONFIG_DEBUG_VM_PAGE_INIT_POISON

Dave Hansen
2018-09-06T16:12:06Z

On 09/06/2018 08:13 AM, Michal Hocko wrote:
>> CONFIG_DEBUG_VM_SLOW_AS_HECK
>>
>> under which we can put this an other really slow VM debugging. Or, we
>> need some kind of boot-time parameter to trigger the extra checking
>> instead of a new CONFIG option.
> I strongly suspect nobody will ever enable such a scary looking config
> TBH. Besides I am not sure what should go under that config option.

OK, so call it CONFIG_DEBUG_VM2, or CONFIG_DEBUG_VM_MORE. :)

What do we put under it? The things that folks complain about that get
turned on with DEBUG_VM, like this.

> Is this worth a separate config option almost nobody is going to
> enable?
Yes. We get basically *zero* debug checking from this option. We want
it available to developers mucking with boot and hotplug, but it's
honestly not worth it for normal users.

Has anyone ever seen a single in-the-wild report from this mechanism?