From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: Regarding UBI scalability From: Artem Bityutskiy To: Kyungmin Park In-Reply-To: <9c9fda240902080231r51c4bcf3o37c0044bf9d924ee@mail.gmail.com> References: <7824366.270131233573513030.JavaMail.weblogic@epml10> <49896448.20407@nokia.com> <6b5362aa0902050140q3c6cbe85ye03d9b5ee59c7f48@mail.gmail.com> <71cd59b00902080148l5304b4eie4dd3868ec12337e@mail.gmail.com> <9c9fda240902080231r51c4bcf3o37c0044bf9d924ee@mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 09 Feb 2009 10:46:22 +0200 Message-Id: <1234169182.17790.92.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: AMIT KUMARSHARMA , "linux-mtd@lists.infradead.org" , Adrian Hunter , Corentin Chary , Brijesh Singh Reply-To: dedekind@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sun, 2009-02-08 at 19:31 +0900, Kyungmin Park wrote: > One more requested feature. > How about to scan ubi image and bad block table at simultaneously? > Now there's two full device scan, bbt and ubi at booting time. > As internal LEA mapping layout, how about to add bbt layout? > > It's also helpful to MLC since MLC doesn't have read oob so it calls > page read command to build bbt. > As you know it takes long time. > > I'm not sure if internal LEA maping is supported, it's meaningful work or not. > > How do you think? Well, doing scanning twice is not very good indeed. I guess what you could do is to make MTD avoid scanning and building the bad block table at all and build it lazily. But then you need 2 bits per eraseblock, not just one. IOW, sure, it is possible to optimize this. -- Best regards, Artem Bityutskiy (Битюцкий Артём)