UBI FS mounting time
Adrian Hunter
adrian.hunter at nokia.com
Wed Jul 22 05:19:04 EDT 2009
Canella Matteo wrote:
> Just to understand if we're doing things in the right way...
> we need more than 6 secs to mount 1 GB Nand Flash.
> Does this sound a normal timing?
Yes
> This is the dmesg of the flash mounting:
>
> [ 6.694626] UBI: attaching mtd10 to ubi2
> [ 6.698594] UBI: physical eraseblock size: 131072 bytes (128 KiB)
> [ 6.705712] UBI: logical eraseblock size: 126976 bytes
> [ 6.711154] UBI: smallest flash I/O unit: 2048
> [ 6.715894] UBI: sub-page size: 512
> [ 6.720533] UBI: VID header offset: 2048 (aligned 2048)
> [ 6.726564] UBI: data offset: 4096
> [ 12.802282] UBI: attached mtd10 to ubi2
> [ 12.806179] UBI: MTD device name: "nand"
> [ 12.814531] UBI: MTD device size: 1024 MiB
> [ 12.820304] UBI: number of good PEBs: 8185
> [ 12.825069] UBI: number of bad PEBs: 7
> [ 12.829495] UBI: max. allowed volumes: 128
> [ 12.834144] UBI: wear-leveling threshold: 4096
> [ 12.838891] UBI: number of internal volumes: 1
> [ 12.843425] UBI: number of user volumes: 1
> [ 12.847860] UBI: available PEBs: 0
> [ 12.852325] UBI: total number of reserved PEBs: 8185
> [ 12.857340] UBI: number of PEBs reserved for bad PEB handling: 81
> [ 12.863479] UBI: max/mean erase counter: 6/3
> [ 12.867807] UBI: background thread "ubi_bgt2d" started, PID 911
The possibility exists to double the eraseblock size by treating 2 eraseblocks as
though it was 1. That should halve the UBI load time to 3 seconds but it would
use a bit more memory in UBIFS. Of course you could double again, with yet
more memory required by UBIFS.
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