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Date:   Sat, 10 Apr 2021 09:25:52 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Mel Gorman <mgorman@techsingularity.net>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Linux-MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Oscar Salvador <osalvador@suse.de>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        David Hildenbrand <david@redhat.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Alexander Duyck <alexander.h.duyck@linux.intel.com>,
        Minchan Kim <minchan@kernel.org>
Subject: Re: [PATCH] mm/memory_hotplug: Make unpopulated zones PCP structures
 unreachable during hot remove
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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