The problem that I didn't think out
Artem B. Bityutskiy
dedekind at yandex.ru
Sun Nov 27 08:20:19 EST 2005
Ferenc, Greetings!
> We had some time, so we read the plan of JFFS3 (with RaiserFS
> documentation).
Oh, what a delightful news! :-)
> The key compression is the only one in the plan that I think that is
> better if we don't use. I think to make key management as simple and
> fast as possible is more important than some percent in flash usage. (if
> I am right the bottleneck of real products is not the flash usage but
> the speed) But it is small techniqual question.
Well, I would not agree, compression Guru Ferenc though you be :-) When
you start thinking about GC, you'll notice that Indexing nodes are to be
rewritten *a great deal* of times. So, the smaller is the index, the
faster is JFFS3. The main idea of key compression is *not* to save flash
space, but to lessen the (index size)/(data size) ratio.
Nonetheless, tests should show the worthiness of keys compression. There
is obviously a (CPU time) vs. (amount of flash IO) trade-off. Thus, I
offer to wait for a JFFS3 prototype and evaluate this. Let's mark this
stuff as "to be evaluated".
> The big questions are that questions you already thinging on: garbage
> collection and wear leveling. Without solving them JFFS3 have no nice
> future. I only would like to say that now we are also thinking on these
> important problems... and we will write if anything usable found. (I may
> be better feeling to thinking on someting not alone... :) )
Great! :-)
Thank you for this feedback.
--
Best Regards,
Artem B. Bityutskiy,
St.-Petersburg, Russia.
More information about the linux-mtd
mailing list