Messages in this thread | | | Date | Wed, 21 Mar 2007 12:05:29 +0100 | From | Jörn Engel <> | Subject | Re: [PATCH 00/22 take 3] UBI: Unsorted Block Images |
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On Tue, 20 March 2007 01:42:46 +0100, Thomas Gleixner wrote: > On Mon, 2007-03-19 at 17:32 -0500, Matt Mackall wrote: > > > > > 4. JFFS2 has its own wear-leving scheme, as do several other > > > > filesystems, so they probably want to bypass this piece of the stack. > > > > > > JFFS2 on top of UBI delegates the wear levelling to UBI, as JFFS2s own > > > wear levelling sucks. > > > > Ok, fine. How about LogFS, then? > > LogFS can easily leverage UBI's wear algorithm.
Ok, now we have reached the absurd. UBI quite fundamentally cannot do wear leveling as good as LogFS can. Simply because UBI has zero knowledge of the _contents_ of its blocks. Knowing whether a block is 90% garbage or not makes a great difference.
Also LogFS currently requires erasesizes of 2^n.
Thomas, I can give you my opinion on this flamewar in private - after you have cooled off.
Jörn
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