Re: [PATCH AUTOSEL 4.14 62/95] mm, memory_hotplug: initialize struct pages for the full memory section

Sasha Levin
2019-05-07T17:18:10Z

On Tue, May 07, 2019 at 10:15:19AM -0700, Linus Torvalds wrote:
>On Tue, May 7, 2019 at 10:02 AM Sasha Levin <sashal@kernel.org> wrote:
>>
>> I got it wrong then. I'll fix it up and get efad4e475c31 in instead.
>
>Careful. That one had a bug too, and we have 891cb2a72d82 ("mm,
>memory_hotplug: fix off-by-one in is_pageblock_removable").
>
>All of these were *horribly* and subtly buggy, and might be
>intertwined with other issues. And only trigger on a few specific
>machines where the memory map layout is just right to trigger some
>special case or other, and you have just the right config.
>
>It might be best to verify with Michal Hocko. Michal?

Michal, is there a testcase I can plug into kselftests to make sure we
got this right (and don't regress)? We care a lot about memory hotplug
working right.

--
Thanks,
Sasha