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From:   Pintu Agarwal <pintu.ping@gmail.com>
Date:   Mon, 5 Nov 2018 20:31:46 +0530
Message-ID: <CAOuPNLjuM5qq3go9ZFZcK0G5pQxTQb0DY36xu+8SL4vC4zJntw@mail.gmail.com>
Subject: Creating compressed backing_store as swapfile
To:     linux-mm@kvack.org, open list <linux-kernel@vger.kernel.org>,
        kernelnewbies@kernelnewbies.org
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Hi,

I have one requirement:
I wanted to have a swapfile (64MB to 256MB) on my system.
But I wanted the data to be compressed and stored on the disk in my swapfile.
[Similar to zram, but compressed data should be moved to disk, instead of RAM].

Note: I wanted to optimize RAM space, so performance is not important
right now for our requirement.

So, what are the options available, to perform this in 4.x kernel version.
My Kernel: 4.9.x
Board: any - (arm64 mostly).

As I know, following are the choices:
1) ZRAM: But it compresses and store data in RAM itself
2) frontswap + zswap : Didn't explore much on this, not sure if this
is helpful for our case.
3) Manually creating swapfile: but how to compress it ?
4) Any other options ?


Thanks,
Pintu