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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 26 Apr 2017 16:12:59 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
To:     Minchan Kim <minchan@...nel.org>
Cc:     Joonsoo Kim <js1304@...il.com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        linux-kernel@...r.kernel.org, kernel-team@....com
Subject: Re: [PATCH v4 2/4] zram: implement deduplication in zram

On (04/26/17 15:29), Minchan 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.

looks good to me.

> 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?

personally, I don't think anyone cares :) the numbers are different
(and, apparently, not quite accurate) all the time. my point was that
stats were not represented in a very convenient way and I agree with
the proposed change.

	-ss