Re: [PATCH] memory-hotplug: Fix bad area access on dissolve_free_huge_pages()

From: Dave Hansen
Date: Wed Sep 21 2016 - 12:33:02 EST

On 09/21/2016 09:27 AM, Michal Hocko wrote:
> That was not my point. I wasn't very clear probably. Offlining can fail
> which shouldn't be really surprising. There might be a kernel allocation
> in the particular block which cannot be migrated so failures are to be
> expected. I just do not see how offlining in the middle of a gigantic
> page is any different from having any other unmovable allocation in a
> block. That being said, why don't we simply refuse to offline a block
> which is in the middle of a gigantic page.

Don't we want to minimize the things that can cause an offline to fail?
The code to fix it here doesn't seem too bad.