Re: [RFC][PATCH v2 2/3] zram: use zs_get_huge_class_size_watermark()

From: Sergey Senozhatsky
Date: Sun Feb 21 2016 - 21:04:39 EST


On (02/22/16 10:59), Sergey Senozhatsky wrote:
[..]
> > > > Having said that, I agree your claim that uncompressible pages
> > > > are pain. I want to handle the problem as multiple-swap apparoach.
> > >
> > > zram is not just for swapping. as simple as that.
> >
> > Yes, I mean if we have backing storage, we could mitigate the problem
> > like the mentioned approach. Otherwise, we should solve it in allocator
> > itself and you suggested the idea and I commented first step.
> > What's the problem, now?
>
> well, I didn't say I have problems.
> so you want a backing device that will keep only 'bad compression'
> objects and use zsmalloc to keep there only 'good compression' objects?
> IOW, no huge classes in zsmalloc at all?

hm, in the worst case we can have _for example_ 80+% of writes to be 'bad
compression'. that turns zsmalloc into a 3rd wheel, and makes it almost
unneeded. hm, may be it's better for now to fix zsmalloc-zram pair.

-ss