Re: Kernel SCM saga..

Willy Tarreau
2005-04-09T07:37:43Z

On Fri, Apr 08, 2005 at 11:56:09AM -0700, Chris Wedgwood wrote:
> On Fri, Apr 08, 2005 at 11:47:10AM -0700, Linus Torvalds wrote:
>
> > Don't use NFS for development. It sucks for BK too.
>
> Some times NFS is unavoidable.
>
> In the best case (see previous email wrt to only stat'ing the parent
> directories when you can) for a current kernel though you can get away
> with 894 stats --- over NFS that would probably be tolerable.
>
> After claiming such an optimization is probably not worth while I'm
> now thinking for network filesystems it might be.

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 :-(

Willy