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From: "Jörn Engel" <joern@wohnheim.fh-wedel.de>
To: Josh Boyer <jwboyer@gmail.com>
Cc: Dmitry Bazhenov <atrey@emcraft.com>, linux-mtd@lists.infradead.org
Subject: Re: JFFS2 node versioning problem?
Date: Wed, 3 May 2006 17:21:51 +0200	[thread overview]
Message-ID: <20060503152151.GC5250@wohnheim.fh-wedel.de> (raw)
In-Reply-To: <625fc13d0605030807q43ee416bo8cb1dcf9f2a71645@mail.gmail.com>

On Wed, 3 May 2006 10:07:22 -0500, Josh Boyer wrote:
> 
> What Artem was asking is if it was physically possible to have a
> file/directory with 4294967296 versions to being with.  Take a 1 byte
> file as an example.  If that was the only file on the whole device,
> and you had that many versions of it you'd have:
> 
> 68 bytes overhead per version + 1 byte of data per version =

68 bytes + 1 byte + 3 bytes padding

> 296352743424 bytes required to store.

309237645312

> That's 276 GiB.  Which isn't even sane for JFFS2 anyway.

Divided by 100k erase cycles:
3.092.376

3MiB is not that insane at all.  Yes, we can theoretically run into
this problem.  But the probability is fairly low.  I'm not too worried
about this.

Jörn

-- 
Measure. Don't tune for speed until you've measured, and even then
don't unless one part of the code overwhelms the rest.
-- Rob Pike

      parent reply	other threads:[~2006-05-03 15:22 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-05-03 11:56 JFFS2 node versioning problem? Dmitry Bazhenov
2006-05-03 12:02 ` Artem B. Bityutskiy
2006-05-03 14:28   ` Dmitry Bazhenov
2006-05-03 14:35     ` Dmitry Bazhenov
2006-05-03 14:42       ` Artem B. Bityutskiy
2006-05-03 14:40     ` Artem B. Bityutskiy
2006-05-03 15:07       ` Dmitry Bazhenov
2006-05-03 15:07     ` Josh Boyer
2006-05-03 15:11       ` Josh Boyer
2006-05-03 15:21       ` Jörn Engel [this message]

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