From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.105.134] helo=mgw-mx09.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1LN5AY-0004Q5-Bs for linux-mtd@lists.infradead.org; Wed, 14 Jan 2009 12:48:28 +0000 Subject: Re: about the _dtype_ parameter From: Artem Bityutskiy To: xiaochuanxv In-Reply-To: <1231952548.3615.66.camel@localhost.localdomain> References: <1231168447.6608.26.camel@localhost.localdomain> <70B175DB52584932819754004995AB59@PC200810230421> <1231839695.5973.15.camel@localhost.localdomain> <1231952548.3615.66.camel@localhost.localdomain> Content-Type: text/plain; charset="UTF-8" Date: Wed, 14 Jan 2009 14:48:39 +0200 Message-Id: <1231937319.5973.67.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-mtd Reply-To: dedekind@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2009-01-15 at 01:02 +0800, xiaochuanxv wrote: > Sorry, a mistake in writing: > > (Suppose wr-ratio represent the ratio of erasures due to wear-leveling > to erasure total physical erase-block erasures. ) > I found that when most of the @dtype is equal to UBI_SHORTTERM, the > wr-ratio is approximately equal to 0.1%, whereas is greater than > > 0.4% > > when @dtype is always UBI_UNKNOWN. It seem that the data type call-back > policy does NOT make any sense in the current implementation. Hmm, interesting observation. I would suggest you to add statistics support to UBI. Introduce a counter for the amount of times UBI moves PEB data, and expose it via sysfs. You may probably add other counters like number of erasures and so on. Then it will be easier to do testing and investigations. -- Best regards, Artem Bityutskiy (Битюцкий Артём)