more lost dotdot caching pessimizes nfs especially

[Bruce Evans]

On Tue, 23 Jan 2007, Kostik Belousov wrote:

> On Wed, Jan 24, 2007 at 12:18:38AM +1100, Bruce Evans wrote:
>> I suspect that recent locking fixes near dotdot are responsible for
>> slowing down builds over nfs even further by increasing the number
>> of RPCs.  Times and RPC counts for building a RELENG_4 kernel under
>> -current on a Turion X2 2GHz:

Nevermind, it was an editing error that lost all the non-hack part of
my RPC reductions.  This lost about half of them.

> could you confirm that reversal of rev. 1.97 of vfs_lookup.c would restore
> the old Lookup/Access RPC statistic ?

Thanks for the quick reply.  I tried that first.  It had no effect.

While you are here I'll ask for a non-hack to restore caching of dotdot :-).
(I just back out rev.1.103 of vfs_cache.c).

Bruce