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Date:   Tue, 27 Jul 2021 14:01:35 +0200
From:   Pavel Machek <pavel@ucw.cz>
To:     David Hildenbrand <david@redhat.com>
Cc:     Michal Hocko <mhocko@suse.com>, Evan Green <evgreen@chromium.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alex Shi <alexs@kernel.org>,
        Alistair Popple <apopple@nvidia.com>,
        Jens Axboe <axboe@kernel.dk>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Miaohe Lin <linmiaohe@huawei.com>,
        Minchan Kim <minchan@kernel.org>,
        Vlastimil Babka <vbabka@suse.cz>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linux-api@vger.kernel.org
Subject: Re: [PATCH v2] mm: Enable suspend-only swap spaces
Message-ID: <20210727120135.GA32265@duo.ucw.cz>
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Hi!

> > Could you expand some more on why a strict exclusion is really
> > necessary? I do understand that one might not want to have swap storage
> > available all the time but considering that swapon is really a light
> > operation so something like the following should be a reasonable
> > workaround, no?
> > 	swapon storage/file
> > 	s2disk
> > 	swapoff storage
>=20
> I'm certainly not a hibernation expert, but I'd guess this can also be
> triggered by HW events, so from the kernel and not only from user space
> where your workaround would apply.

I should know about hibernation, and I'm not aware of any case where
we do hibernation from kernel. Userspace should be always involved.

Best regards,
								Pavel

--=20
http://www.livejournal.com/~pavelmachek

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