jffs2_scan_make_ino_cache() in scan.c very slow

[David Woodhouse]

joakim.tjernlund at lumentis.se said:
>  I have made some crude measures in jffs2_scan_medium() and friends to
> see where most of the time is spent. It turns out that
> jffs2_scan_make_ino_cache() is takes about 50 % of the total mount
> time!

How did you do your profiling? Are you sure it's not spending the time in 
jffs2_get_ino_cache() and jffs2_add_ino_cache()? I suspect it is.

> What can be done to decrease this time? 

Try increasing INOCACHE_HASHSIZE - that'll make the hash table more 
efficient - well, it'll make the hash table into a hash table instead of a 
linked list :)

You'll probably find that it's looking up the same inode over and over 
again too - in which case caching the last used inode in 
jffs2_scan_make_ino_cache() would probably be useful.



joakim.tjernlund at lumentis.se said:
>  PS.
>     I sent a patch (Subject:  cfi_cmdset0001.c: bug fixes and new
> features) a week ago
>     and I haven't got any comments so far.


Sorry. Can you make sure it still applies to the current CVS tree and 
resend it?

--
dwmw2