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Subject: Re: Is there possible to integrate mtd ubi ubifs latest version in
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From: Artem Bityutskiy <dedekind@infradead.org>
To: Nancy <nancydreaming@gmail.com>
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Date: Wed, 16 Apr 2008 09:11:09 +0300
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On Tue, 2008-04-15 at 08:04 -0400, Nancy wrote:
> >  Then first of all you cannot use the default 4096 UBI WL threshold. Ma=
ke
> >  it 256 for example. 4K is almost lifetime of your eraseblock!
>        Why 4K is almost lifetime of my eraseblock? the specs says 10K,
> how you result that number 4?
I meant they are close and you should use something an order of
magnitude less then 4K.

>        How to set the WL threshold? any equation?
No equation. I'd suggest 256 for you. There is a configuration option
for this.

>        When eraseblock counter exceed 2*WL threshold, it will be less
> used, move its data to seldom used eraseblock?
>        Why WL can't just simply pick up the min used PEB to be the
> next block to use?

Consider a situation when you have static data, which never changes, and
it sits a a subset of eraseblock N, while the rest of the flash is
intensively used. In this case UBI moves data from N to more worn-out
eraseblocks, and start using N. And the threshold says which should be
the difference between erase-counter of eraseblocks N and the other
ones, roughly speaking.

--=20
Best regards,
Artem Bityutskiy (=D0=91=D0=B8=D1=82=D1=8E=D1=86=D0=BA=D0=B8=D0=B9 =D0=90=
=D1=80=D1=82=D1=91=D0=BC)