> On Oct 18, 2019, at 2:35 AM, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> wrote:
> 
> You're right, then I don't see how this happens. If the error hugepage was
> isolated without having PG_hwpoison set, it's unexpected and problematic.
> I'm testing myself with v5.4-rc2 (simply ran move_pages12 and did hotremove/hotadd)
> but don't reproduce the issue yet.  Do we need specific kernel version/config
> to trigger this?

This is reproducible on linux-next with the config. Not sure if it is reproducible on x86.

https://raw.githubusercontent.com/cailca/linux-mm/master/powerpc.config

and kernel cmdline if that matters

page_poison=on page_owner=on numa_balancing=enable \
systemd.unified_cgroup_hierarchy=1 debug_guardpage_minorder=1 \
page_alloc.shuffle=1

BTW, where does the code set PG_hwpoison for the head page?