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

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Date:   Wed, 26 Apr 2017 16:39:44 +0900
From:   Minchan Kim <minchan@...nel.org>
To:     Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
Cc:     Joonsoo Kim <js1304@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        LKML <linux-kernel@...r.kernel.org>, kernel-team@....com
Subject: Re: [PATCH v4 2/4] zram: implement deduplication in zram

On Wed, Apr 26, 2017 at 04:21:47PM +0900, Sergey Senozhatsky wrote:
> 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.

After Andrew takes dedup patchset, I will fix it later.
Thanks.