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From:   Vitaly Wool <vitaly.wool@konsulko.com>
Date:   Wed, 20 May 2020 10:23:38 +0200
Message-ID: <CAM4kBBJSEpB9kS+PKpd5HJT0Ox5rNWW2vsvHTVUw7Q59C-ktig@mail.gmail.com>
Subject: Re: zswap z3fold + memory offline = infinite loop
To:     Qian Cai <cai@lca.pw>
Cc:     Michal Hocko <mhocko@suse.com>,
        David Hildenbrand <david@redhat.com>,
        Linux-MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Minchan Kim <minchan@kernel.org>,
        Seth Jennings <sjenning@redhat.com>,
        Dan Streetman <ddstreet@ieee.org>
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On Tue, May 19, 2020 at 5:50 AM Qian Cai <cai@lca.pw> wrote:
<snip>
>
> >
> > Removing that check in ->isolate() is not a big deal, but ->migratepage() shall not allow actual migration anyway if there are mapped objects.
>
> Is that worse than an endless loop here?

Well, let's figure if there really has to be an endless loop. Would
you mind retesting with
https://marc.info/?l=linux-mm&m=158996286816704&w=2?

Best regards,
   Vitaly