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

From: Minchan Kim
Date: Tue Aug 23 2016 - 21:08:27 EST


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.