From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.122.233] helo=mgw-mx06.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1OC8Iw-0008Dr-4T for linux-mtd@lists.infradead.org; Wed, 12 May 2010 09:32:41 +0000 Subject: Re: UBIL design doc From: Artem Bityutskiy To: Thomas Gleixner In-Reply-To: References: <1273475736.2209.88.camel@localhost> <1273650099.22706.41.camel@localhost> Content-Type: text/plain; charset="UTF-8" Date: Wed, 12 May 2010 12:31:15 +0300 Message-ID: <1273656675.22706.62.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Brijesh Singh , rohitvdongre@gmail.com, linux-mtd@lists.infradead.org Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2010-05-12 at 11:06 +0200, Thomas Gleixner wrote: > On Wed, 12 May 2010, Artem Bityutskiy wrote: > > On Tue, 2010-05-11 at 21:17 +0200, Thomas Gleixner wrote: > > > > > > Also chaining has a tradeoff. The more chains you need to walk the > > > closer you get to the point where you are equally bad as a full scan. > > > > Well, every new chain member reduces the superblock wear speed by order > > 2, so I the chain would have 2-4 eraseblocks in most cases, I guess, > > which is not bad. > > > > In the opposite, moving the SB 3-4 eraseblocks further only reduces the > > load merely by factor 3-4. > > Right, but having the flexibility of moving the super block in the > first 16 or 32 blocks is not going to hurt the attach time > significantly. I'm not against the super block and chain design, I > merily fight fixed address designs. Yeah, I guess this is not a big deal to shift the SB forward a bit if needed. It is not worth discussing further, but to make sure Brijesh is focused on the most important things, I'd like to note that implementation-wise, it is OK to have a constant defined to 1 so far, and later test that everything works just fine when it is something else, and optionally implement the SB searching function. -- Best Regards, Artem Bityutskiy (Артём Битюцкий)