On 7 Apr 2015, stefan@agner.ch wrote:
On 2015-04-07 16:24, Bill Pringlemeir wrote:
The OOB patch also significantly decreases UbiFS mounting time in Linux. I load Linux itself via tftp/network and not using u-boot with nand. I guess I should try that.
Is it UBIFS mounting time or is it bad block scanning? Afaik, it should speed up the latter significantly, but I don't see why it should speed up the former.
It is both,
* no changes.
[0.840632] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xca [0.964838] 0x000001040000-0x000010000000 : "root" .124s
base ubi0 mount is .833585s
* improved READ_OOB
[0.638869] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xca [0.707994] 0x000001040000-0x000010000000 : "root" .069s
base ubi0 mount 1/10s reduction. .738204s
This is for a 256MB device. The Ubi mount/scan time is not completely in-significant.
For instance, here is my last run with improved READ_OOB
[ 0.942538] ubi0: attaching mtd3 ... [ 1.680742] ubi0: background thread "ubi_bgt0d" started, PID 104
This is my 'base ubi0 mount' numbers.
The time is slightly different than what I recorded previously. I booted several times without 'READ_OOB' and the times were consistently '.83xxS'. It is possible that the initial BBT scan being quicker altered something; so it is not UBI use of OOB. I am not sure. I just noted that it was ??significantly?? different.
Regards, Bill Pringlemeir.