linux-kernel - Re: [RFC 0/4] ZRAM: make it just store the high compression rate page

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Message-ID: <20160824010415.GB27022@bbox>
Date:   Wed, 24 Aug 2016 10:04:15 +0900
From:   Minchan Kim <minchan@...nel.org>
To:     Hui Zhu <zhuhui@...omi.com>
Cc:     ngupta@...are.org, sergey.senozhatsky.work@...il.com,
        hughd@...gle.com, rostedt@...dmis.org, mingo@...hat.com,
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Subject: Re: [RFC 0/4] ZRAM: make it just store the high compression rate page

Hi Hui,

On Mon, Aug 22, 2016 at 04:25:05PM +0800, Hui Zhu wrote:
> Current ZRAM just can store all pages even if the compression rate
> of a page is really low.  So the compression rate of ZRAM is out of
> control when it is running.
> In my part, I did some test and record with ZRAM.  The compression rate
> is about 40%.
> 
> This series of patches make ZRAM can just store the page that the
> compressed size is smaller than a value.
> With these patches, I set the value to 2048 and did the same test with
> before.  The compression rate is about 20%.  The times of lowmemorykiller
> also decreased.

I have an interest about the feature for a long time but didn't work on it
because I didn't have a good idea to implment it with generic approach
without layer violation. I will look into this after handling urgent works.

Thanks.