Josh Boyer wrote:
Hamish Moffatt wrote (Message-ID: 20080407073227.GA6317@cloud.net.au):
Sorry I should've said 512MiB perhaps: 512 megabytes. UBI attach time appears to be about 6 seconds.
If 6 seconds is as fast as it can be done, annoying but fair enough.
You should read that thread a bit more carefully. The scan time is highly dependent upon the NAND driver beneath UBI. For example, a UBI scan/attach on a 1GiB device on OLPC was 2 seconds.
Ah, I intended to quote the 2 seconds too but forgot, sorry. I think 2 seconds per gigabyte is a significant time, too, but not so much.
The followup suggested it was due to the speed of the chip, not so much the driver.
Adding _another_ 6 seconds to the boot time seems a lot to me.
You mean adding another "X amount of time depending on factors outside of UBI's control."
Well, yes, that would be a reason to consider whether doing it is a good idea :-)
I can understand the hesitation, but I think 6 seconds just to find the kernel - especially when doing a 'disk resume' - is quite a lot.
You should really stop quoting this 6 second number.
Let's call it 2 seconds per gigabyte, then.
Note that I haven't tried UBI myself yet. I'm going on what has been written to the list so far, as quoted above.
Maybe you should try it :).
I will when good looking figures are being quoted on the list ;-)
-- Jamie