Re: [RFC][PATCH 0/7] UBI checkpointing support

From: Shmulik Ladkani
Date: Thu Mar 08 2012 - 02:08:45 EST


On Wed, 07 Mar 2012 22:19:00 +0100 Richard Weinberger <rw@xxxxxxxxxxxxx> wrote:
> >> All these operations scan a limited number of erase blocks which makes
> >> the UBI init O(1) and independent of the device size.
> >
> > Well, is it really true? The larger is the flash the more you read and
> > process anyway, and it is still linear, but the multiplier becomes very
> > small, so this is a huge improvement.
>
> Yes. :)
>
> Using checkpointing UBI only has to scan a fixed (independent of the
> flash size!) number of blocks.

But doesn't the CP data (sorry, UBIUBI data :) need to have one
'struct ubi_cp_ec' descriptor for each used/free PEB, and as such the
maximum number of 'ubi_cp_ec' descriptors is total device PEBs, meaning
CP data is still linearly scaled to device size (with a very small
multiplier)?

Regards,
Shmulik
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