From mboxrd@z Thu Jan 1 00:00:00 1970 From: Detlev Zundel Date: Mon, 29 Sep 2008 16:05:07 +0200 Subject: [U-Boot] JFFS2-Summary support for u-boot In-Reply-To: (Michael Lawnick's message of "Mon, 29 Sep 2008 11:34:02 +0000 (UTC)") References: <1222680893.31048.8.camel@gentoo-jocke.transmode.se> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Michael, > Joakim Tjernlund 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