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From: Detlev Zundel <dzu@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] JFFS2-Summary support for u-boot
Date: Mon, 29 Sep 2008 16:05:07 +0200	[thread overview]
Message-ID: <m2prmnrqss.fsf@ohwell.denx.de> (raw)
In-Reply-To: <loom.20080929T112829-943@post.gmane.org> (Michael Lawnick's message of "Mon, 29 Sep 2008 11:34:02 +0000 (UTC)")

Hi Michael,

> Joakim Tjernlund <joakim.tjernlund <at> transmode.se> writes:
>
>> 
>> On Mon, 2008-09-29 at 08:45 +0000, Michael Lawnick wrote:
>> > Hi *,
>> > 
>> > please feel free to correct me if I tell sh**:
>> > As far as I was told, bad JFFS2 boot performance of u-boot is result of not
>> > supporting summary. (Because there is no JFFS2 but only JFFS support?)
>> 
>> It is not missing SUMMARY, it is excessive scanning of empty flash
>> blocks. Look at jffs2/scan.c, it only scan the first 4KB or before
>> declaring the block empty.
>
> Ok, did I get you correct:
> The performance difference between u-boot and linux is based on skipping
> senseless scans of empty blocks?
> I've taken a little look into scan.c
> The comment "The code lacks more or less any comment, and is still arcane and
> difficult to read in places." doesn't make me happy.
>
> Has anybody tried to (and succeeded in) speed up u-boot?

We are currently working on such a speedup bringing U-Boot up to par
with Linux.  I am confident that we can post our results in the next
week.

Cheers
  Detlev

PS: Wow, message-mode in Emacs wants a confirmation sending an email to
    you as your address looks bogus ;)

-- 
Emacs is the way to purify your soul using garbage collection.
--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de

  parent reply	other threads:[~2008-09-29 14:05 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-29  8:45 [U-Boot] JFFS2-Summary support for u-boot Michael Lawnick
2008-09-29  9:34 ` Joakim Tjernlund
2008-09-29 11:34   ` Michael Lawnick
2008-09-29 11:54     ` Joakim Tjernlund
2008-09-29 12:49       ` Michael Lawnick
2008-09-29 14:02         ` Joakim Tjernlund
2008-09-30  7:40           ` Michael Lawnick
2008-10-07  1:23             ` Detlev Zundel
2008-09-29 14:05     ` Detlev Zundel [this message]
2008-09-29 18:13       ` Michael Lawnick

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