Re: Kernel SCM saga..

Willy Tarreau
2005-04-09T08:01:20Z

On Sat, Apr 09, 2005 at 05:47:08PM +1000, Neil Brown wrote:
> On Saturday April 9, willy@w.ods.org wrote:
> >
> > I've just checked, it takes 5.7s to compare 2.4.29{,-hf3} over NFS (13300
> > files each) and 1.3s once the trees are cached locally. This is without
> > comparing file contents, just meta-data. And it takes 19.33s to compare
> > the file's md5 sums once the trees are cached. I don't know if there are
> > ways to avoid some NFS operations when everything is cached.
> >
> > Anyway, the system does not seem much efficient on hard links, it caches
> > the files twice :-(
>
> I suspect you'll be wanting to add a "no_subtree_check" export option
> on your NFS server...

Thanks a lot, Neil ! This is very valuable information. I didn't
understand such implications from the exports(5) man page, but it
makes a great difference. And the diff sped up from 5.7 to 3.9s
and from 19.3 to 15.3s.

Cheers,
Willy