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Re: New jffs2 files stay uncompressed?




joakim.tjernlund@xxxxxxx.se said:
> In my tree, the most time is spent scanning empty flash and doing CRC
> on the inodes data part. If there were a way to avoid scanning the
> empty nodes(that is, play with the ACCURATE bit in the  CLEANMARKER
> node) and avoid CRC(CRC is checked at every read request anyway so
> maybe we could just skip the extra CRC check at mount) at mount on
> every files data, the mount would be very fast.

If we can make that work, I'd prefer it to the special case in
jffs2_mark_node_obsolete(). Until now, the ACCURATE bit has been strictly 
an optimisation - you can't do it on NAND flash or even some NOR chips. 
That situation has to work too. 

> BTW, today the CLEANMARKER is optional, is that intentional? If it was
> mandatory it would make life simpler when playing with the erase
> blocks.

It wasn't implemented in the beginning. Making it mandatory would have 
involved a break in compatibility. And mkfs.jffs2 still doesn't emit them.

--
dwmw2



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