Re: [PATCH] mm/memory_hotplug: Make unpopulated zones PCP structures unreachable during hot remove

From: Michal Hocko
Date: Sat Apr 10 2021 - 03:26:41 EST


On Fri 09-04-21 16:12:59, Mel Gorman wrote:
[...]
> If anything, the minimal "fix" is to simply delete IRQ disable/enable on
> the grounds that IRQs protect nothing and assume the existing hotplug
> paths guarantees the PCP cannot be used after zone_pcp_enable(). That
> should be the case already because all the pages have been freed and
> there is nothing to even put into the PCPs but I worried that the PCP
> structure itself might still be reachable even if it's useless which is
> why I freed the structure once they could not be reached via zonelists.

OK. Let's do that for now and I will put a follow up on my todo list.

Thanks!
--
Michal Hocko
SUSE Labs