Re: PUFFS performance on netbsd-6

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

hi,

> YAMAMOTO Takashi <yamt%mwd.biglobe.ne.jp@localhost> wrote:
> 
>> 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.
> 
> I only have PUFFS_KFLAG_NOCACHE_NAME set when calling puffs_init
> 
> On netbsd-5, the kernel never looked up a node twice without reclaiming
> in between. You could have either this behavior (I ommit lookup and
> reclaim on x/y and x/z for the sake of clarity):
> LOOKUP x
> GETATTR x/y
> RECLAIM x
> LOOKUP x
> GETATTR x/z
> RECLAIM x
> 
> Or that one:
> LOOKUP x
> GETATTR x/y
> GETATTR x/z
> RECLAIM x
> 
> But never this new behavior I observe on netbsd-6:
> LOOKUP x
> GETATTR x/y
> LOOKUP x
> GETATTR x/z
> RECLAIM x
> RECLAIM x

the behaviour on netbsd-6 is what i expect with PUFFS_KFLAG_NOCACHE_NAME.
probably the flag is broken on netbsd-5?

having said that, the two consecutive RECLAIMs for the same node seems
strange.  it could be a bug in cookie -> vnode lookup code, which produces
duplicated vnodes for a cookie.

YAMAMOTO Takashi

> 
> -- 
> Emmanuel Dreyfus
> http://hcpnet.free.fr/pubz
> manu%netbsd.org@localhost