Re: Vnode API change: add global vnode cache

[Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>]

"J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost> wrote:
> On 07 Apr 2014, at 17:44, Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>
> wrote:
> 
> > "J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost> wrote:
> >> Currently all file systems have to implement their own cache of
> >> vnode / fs node pairs.  Most file systems use a copy and pasted
> >> version of ufs_ihash.
> >> 
> >> So add a global vnode cache with lookup and remove:
> >> 
> >> <...>
> >> 
> >> Diff implementing this for file systems sharing ufs_ihash and replacing
> >> VFS_VGET()/VOP_UNLOCK() sequences with vcache_lookup() is here:
> >> 
> >> http://www.netbsd.org/~hannken/vnode-pass6-1.diff
> >> 
> >> Comments or objections anyone?
> > 
> > I like this step a lot!
> > 
> > One concern though: can you benchmark ./build.sh on a machine with 8 or
> > more CPUs?  I fear that vcache.lock might be a bit contended and we
> > ought to figure out how much.
> 
> I don't have such a setup.  Contention should be the same as before as
> ufs_ihash did exactly the same.

Fair enough.  A small side note: the lock is per all file systems now,
not only UFS.

-- 
Mindaugas