Subject: Re: results from playing around with the new dirpref code
To: None <tech-perform@netbsd.org>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: tech-perform
Date: 09/03/2001 13:36:47
On Mon, Sep 03, 2001 at 01:15:49PM -0400, Thor Lancelot Simon wrote:
> 
> This doesn't surprise me.  Running out of vnodes forces directory and file
> data writes; having a large number of cylinder groups (because allocation
> is spread ~evenly among the CGs) means that to write an arbitrary file
> you are far more likely to have to seek.  The interaction between the

Another observation: when you have to recycle a vnode, you get one that's
basically chosen at random with regard to the current head position.  This
is REALLY BAD.  To fix it, we'd need to index the vnode cache some other
way than as a hash table, but the fix might give a really large performance
increase in some cases.

Thor