All of lore.kernel.org
 help / color / mirror / Atom feed
From: Matthieu CASTET <matthieu.castet@parrot.fr>
To: Indrek Kruusa <indrek.kruusa@artecdesign.ee>
Cc: linux-mtd@lists.infradead.org
Subject: Re: jffs2 Erase Block Summary overhead
Date: Tue, 20 Feb 2007 09:45:11 +0100	[thread overview]
Message-ID: <45DAB517.70502@parrot.fr> (raw)
In-Reply-To: <200702191310.12647.indrek.kruusa@artecdesign.ee>

Indrek Kruusa a écrit :
> Ühel kenal päeval (neljapäev 15 veebruar 2007 5:30 pm) kirjutas Matthieu 
> CASTET:
>> Hi,
>>
>> after doing some test on a 64MB nand flash, we see that only 50 MB can
>> be stored on the filesystem [1]. The extra 10 MB are taken by jffs2
>> summary. If we disable jffs2 sumary in the kernel, the 10MB become
>> available.
> 
> This is interesting. I have a Puppy Linux build within 52MB (ps 512B/ebs 16KB) 
> and sumtool grows it to 57MB.
> JFFS2/device with ps of 2048B/ebs 128KB has much much better compression level 
> and sum adds ca. 3-4% for this case.
Mine is a ps 512B/ebs 4KB.

> You can play with "dry" mkfs.jffs2 and different page;block sizes/file 
> counts/file types to get the whole picture.
I don't get the same result with image generated with mkfs.jffs2 and on
the fly written file :
- with mkfs.jffs2 + sumtool give me only 7 % overhead
- on the fly write give me 15 % overhead


Matthieu

      reply	other threads:[~2007-02-20  8:45 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-15 15:30 jffs2 Erase Block Summary overhead Matthieu CASTET
2007-02-19 10:05 ` David Woodhouse
2007-02-19 10:58   ` Matthieu CASTET
2007-02-19 11:15     ` Matthieu CASTET
2007-02-19 11:10 ` Indrek Kruusa
2007-02-20  8:45   ` Matthieu CASTET [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=45DAB517.70502@parrot.fr \
    --to=matthieu.castet@parrot.fr \
    --cc=indrek.kruusa@artecdesign.ee \
    --cc=linux-mtd@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.