Re: PUFFS performance on netbsd-6

[yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)]

hi,

> Hi
> 
> I am runnning my usual perfuse test case on netbsd-6: building the 
> netbsd tree. Performances are much lower than on netbsd-5.
> 
> A quick dump of FUSE operations shows that the thing spends most 
> of its time on lookups. It will exhibit behavior like this:
> LOOKUP a
> LOOKUP a/b
> LOOKUP a/b/c
> LOOKUP a/b/c/d
> GETATTR a/b/c/d
> LOOKUP a
> LOOKUP a/b
> LOOKUP a/b/c
> LOOKUP a/b/c/e
> GETATTR a/b/c/e
> 
> It seems that while the kernel still knows about a/b/c (it was not
> reclaimed), it still have to lookup from the root. Is that on purpose?
> If it is, then what is the rationale?

if your filesystem is not using namecache and the application is using
full paths to look up files, the trace looks normal.
otherwise, it looks weird.

YAMAMOTO Takashi

> 
> I have not yet tested on -current.
> 
> -- 
> Emmanuel Dreyfus
> manu%netbsd.org@localhost