Re: [RFC PATCH v1 4/4] mm, memory_hotplug: fix inconsistent num_poisoned_pages on memory hotremove

[HORIGUCHI NAOYA(堀口 直也)]

On Thu, Apr 28, 2022 at 11:20:16AM +0800, Miaohe Lin wrote:
> On 2022/4/27 12:28, Naoya Horiguchi wrote:
> > From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
> > 
> > When offlining memory section with hwpoisoned pages, the hwpoisons are
> > canceled. But num_poisoned_pages is not updated for that event, so the
> > counter becomes inconsistent.
> 
> IIUC, this work is already done via clear_hwpoisoned_pages when __remove_pages.
> Or am I miss something?

Actually I had the same question when writing this patch, and found that
__remove_pages() seems to be called from device memory or HMM, but not from
offline_pages().  If you mean that we could make offline_pages() call
clear_hwpoisoned_pages(), that seems possible and I'll consider it.

But as David and Oscar pointed out for 0/4, removing PageHWPoison flags
in offlining seems not to be right thing, so I'd like to have some consensus
on what way to go first.

Thanks,
Naoya Horiguchi