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Date:   Wed, 4 Aug 2021 07:35:27 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Bart Van Assche <bvanassche@acm.org>
Cc:     Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
        Christoph Hellwig <hch@lst.de>,
        Jaegeuk Kim <jaegeuk@kernel.org>,
        Ming Lei <ming.lei@redhat.com>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        Martijn Coenen <maco@android.com>
Subject: Re: [PATCH v2 2/3] loop: Select I/O scheduler 'none' from inside
 add_disk()
Message-ID: <20210804053527.GA5711@lst.de>
References: <20210803182304.365053-1-bvanassche@acm.org> <20210803182304.365053-3-bvanassche@acm.org>
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On Tue, Aug 03, 2021 at 11:23:03AM -0700, Bart Van Assche wrote:
> We noticed that the user interface of Android devices becomes very slow
> under memory pressure. This is because Android uses the zram driver on top
> of the loop driver for swapping,

Sorry, but that is just amazingly stupid.  If you really want to swap
to compressed files introduce that support in the swap code instead of
coming up with dumb driver stacks from hell.