From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: Should flash hardware look like UBI? From: David Woodhouse To: Thomas Gleixner In-Reply-To: References: <1254751504.13096.725.camel@macbook.infradead.org> <1254830713.14541.1195.camel@macbook.infradead.org> Content-Type: text/plain Date: Tue, 06 Oct 2009 14:07:52 +0100 Message-Id: <1254834472.14541.1331.camel@macbook.infradead.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Cc: linux-mtd List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2009-10-06 at 14:56 +0200, Thomas Gleixner wrote: > > I guess the bad block hiding might work, but I'm concerned about the > wear levelling aspect. That's what they usually fail to do in a > sensible way. When the resulting carefully hidden and obscured > algorithm is just contrary to what the filesystem expects you are > again digging holes in your device within no time. Yeah. It makes a lot of sense for the wear levelling to be done explicitly by the OS, not in the device. So maybe we don't want the interface to be _quite_ like UBI. But if we can let the device handle _some_ of the aspects of the logical<->physical translation, that would be interesting. Partly because it could do the full scan of the device at startup _internally_, and it wouldn't slow down the OS. I'd be happy with limiting it to _just_ what hard drives to; ECC and a 1:1 remapping of blocks. Basically 'hardware acceleration for UBI'. -- dwmw2