jffs2_scan_make_ino_cache() in scan.c very slow

[Joakim Tjernlund]

> 
> 
> 
> 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?
I accumulated the difference of jiffies from the entry of jffs2_scan_make_ino_cache()
to it returned.

 Are you sure it's not spending the time in 
> jffs2_get_ino_cache() and jffs2_add_ino_cache()? I suspect it is.

That is so, allmost all time is in jffs2_get_ino_cache().

> 
> > 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.

OK, will try an see what happens.
> 
> 
> 
> 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?

Well, I not using the current CVS at the moment. It will take some time
until I upgrade again.

 Jocke

> 
> --
> dwmw2
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