Re: JFFS2 mount time

[Steven Scholz <steven.scholz@imc-berlin.de>]

Hi,


>> Thanks a million. I'll try that. I guess I can just use your Patch on 
>> a vanilla linux-2.6.10!?
>>
>> BTW: On the link mentioned above I read "Speed up the mount time of 
>> JFFS2 - specially when it uses NAND flash. " How about NOR flash?
>>
> My understanding of the problem is that summary may help in case of NOR, 
> but in
> general it shouldn't increase the mount speed a lot (am I wrong?).

As I wrote in another thread the summary patch reduced the mount time from 6 
seconds to less than 1 second on my embedded ARM9 system with 8MB NAND flash.
But now GC still slows down the start up of user applications as it checks all 
CRCs right after booting.

> If we change
> the patch a bit (asking not to check any CRC in the block has summary) 
> we may
> have better mount speed (and iget()). And possibly in case of nor we 
> even doesn't
> need to store any data in summary - only header. Header will show us 
> that the block
> was successfully written (no unclean reboots) and we my trust it and do 
> not check CRC.

Makes sense to me.
Ferenc, what do you think about that?
No need to check CRC if we have a summary, right?
This could fix my GC problem mentioned above and in the thread
http://lists.infradead.org/pipermail/linux-mtd/2005-January/011411.html

--
Steven