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Date:   Wed, 20 May 2020 15:05:56 -0400
From:   Qian Cai <cai@lca.pw>
To:     Vitaly Wool <vitaly.wool@konsulko.com>
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>
Subject: Re: zswap z3fold + memory offline = infinite loop
Message-ID: <20200520190556.GB4894@Qians-MacBook-Air.local>
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On Wed, May 20, 2020 at 10:23:38AM +0200, Vitaly Wool wrote:
> 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?

The patch does not help. Running the reproducer the second time would still
trigger the looping.