From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.122.230] helo=mgw-mx03.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1OC8lh-00079c-OM for linux-mtd@lists.infradead.org; Wed, 12 May 2010 10:02:23 +0000 Subject: Re: UBIL design doc From: Artem Bityutskiy To: Brijesh Singh In-Reply-To: References: <1273475736.2209.88.camel@localhost> <1273650099.22706.41.camel@localhost> <1273653341.22706.46.camel@localhost> Content-Type: text/plain; charset="UTF-8" Date: Wed, 12 May 2010 13:01:21 +0300 Message-ID: <1273658481.22706.73.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Thomas Gleixner , linux-mtd@lists.infradead.org, rohitvdongre@gmail.com 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 15:19 +0530, Brijesh Singh wrote: > >> Any thing goes bad, normal scanning becomes recovery. > >> 5) Not sure if log is required in first place. But it could be an option. > >> Is that correct? > > > > No, at least I did not suggest you to get rid of the log. It is needed > > to handle unclean reboots. > Log is written for each EC or VID change. Yes, I understand. > Frequency of log write is same as > the frequency of these headers. Right. > In case we keep both, there will be one log > write penalty per write/erase. Yes, each time you write to an unmapped LEB, you write the VID header and a log entry. > So write performance will drop considerably. Not sure about 'considerably'. This is to be tested. Keeping the headers means 1 additional write per peb_size bytes, right? Plus just after erase, EC header should be written. But this is the price you pay for robustness and compatibility. But again, it is very easy to switch off headers if this is needed, isn't it? -- Best Regards, Artem Bityutskiy (Артём Битюцкий)