[Yaffs] Re: yaffs2 status

[Wookey]

+++ Nick Bane [05-04-18 17:30 +0100]:
> > Hi,
> > 
> > > For best mount-time splitting your flash into more than one partition is
> > > often smart so you can boot from a small partition and give 
> > user feedback
> > > whilst mounting a larger data partition. Obviously this doesn't suit all
> > > applications.
> > 
> > Can anybody post any reference numbers? For example it takes me 20+
> > minutes to mount 256 MByte NAND partion with a 200 MByte file on it
> > when using jffs2.
> > Any idea what I may gain by moving to yaffs2?
> > 
> These results are using yaffs1. 
> I expect the process to be faster using yaffs2 due to the faster interface and smaller number of headers to scan.
> We have 128MByte nand chips fairly full and they don't take forever to scan. 
> This is anecdotal but my impression is of the order of 10 secs.
> The poor boot time scaling of jffs2 and large amounts or ram used were prime reasons why we sponsored the yaffs effort.
> We are very pleased with the results.
> 
> I just asked one of the testers and he says that the mounting pause during boot up is about 8 secs with 77MB used.

That's with a 200Mhz Strongarm and software ecc, btw, for comparison.

Another datapoint I have is a 400Mhz xscale and 64Mb of NAND flash using
JFFS2. The root is a 56Mb partition and is completely full (2.7x
compression). I reckon that takes ~30s for cold boot scan, but I haven't
actually measured it. I haven't tried YAFFS on this hardware.

Wookey
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