Re: [PATCH v2] mm/hwpoison: reset hwpoison filter parameters in pfn_inject_exit()

[Miaohe Lin]

On 2024/7/16 16:38, Michal Hocko wrote:
> On Tue 16-07-24 11:35:16, Miaohe Lin wrote:
>> When hwpoison_inject module is removed, hwpoison_filter_* parameters
>> should be reset. Otherwise these parameters will have non-default values
>> at next insmod time.
> 
> There is a clear layering broken here. We have mm/memory-failure.c using
> values and mm/hwpoison-inject.c defining the values. Both with a
> potentially different life time. Shouldn't that be fix instead?

In fact, we have mm/memory-failure.c defining and using these values while they can
only be modified through mm/hwpoison-inject.c from userspace. The common usecase should be:

1. User set hwpoison filter parameters first through mm/hwpoison-inject.c.
2. Then doing memory hwpoison test through mm/hwpoison-inject.c.

hwpoison_filter_* parameters are only used for test from userspace. From this perspective,
this potentially different life time doesn't break anything. Or am I miss something?

Thanks.
.