Re: [PATCH v4 2/4] zram: implement deduplication in zram

From: Sergey Senozhatsky
Date: Wed Apr 26 2017 - 03:22:13 EST


On (04/26/17 15:59), Joonsoo Kim wrote:
[..]
> > Actually, I found it for the last review cycle but didn't say that
> > intentionally. Because it is also odd to me that pages_stored isn't
> > increased for same_pages so I thought we can fix it all.
> >
> > I mean:
> >
> > * normal page
> > inc pages_stored
> > inc compr_data_size
> > * same_page
> > inc pages_stored
> > inc same_pages
> > * dedup_page
> > inc pages_stored
> > inc dup_data_size
> >
> > IOW, pages_stored should be increased for every write IO.
> > But the concern is we have said in zram.txt
> >
> > orig_data_size uncompressed size of data stored in this disk.
> > This excludes same-element-filled pages (same_pages) since
> > no memory is allocated for them.
> >
> > So, we might be too late. :-(
> > What do you think about it?
> > If anyone doesn't have any objection, I want to correct it all.
>
> I have no objection.
> If so, do I need to postpone this patchset until others are fixed?

this probably will mess with your series a lot. so I don't mind if you or
Minchan will send stats-fixup patch after the dedup series. may be/preferably
as the last patch in the series. but if you or Minchan want to fix stats
first, then I wouldn't mind either. I just don't make a big deal out of those
stats, a bunch of fun to know numbers. my 5cents.

-ss