Subject: Re: bumping default open descriptors
To: <>
From: David Laight <>
List: tech-kern
Date: 04/05/2004 22:00:30
On Fri, Apr 02, 2004 at 10:15:49PM +1000, matthew green wrote:
> hi folks.
> i think it's beyond time netbsd increased the default fd's per process.
> i'd like to make a change along these lines, but first i'd like to
> collect some input on:
> 	- currently it's 64, raise to what?  128?  256?  i'm vaguely
> 	inclined to make it 256 but i'd also like to allow MD code to
> 	lower the limit back to 64 if they want (is this actually
> 	necessary?)

You need to pick values for both the hard and soft limits, remember
an unprived process can set the soft limit to the hard one - this
has the obvious effect...

Any process than expects to use a lot of fds should (probably) set the
soft limit to the hard limit anyway.

> 	- increasing this may mean we want to increase the size of
> 	the total descriptor table.  i don't expect it would be the
> 	same order of change, ie, 2* max fds -> 1.3* total fds, etc,
> 	as the point of this isn't that we can't open enough files,
> 	but that a single process can't.  (this is part of why i
> 	prefer a default of 256.)

Why is there a limit (other than kmem) on that table?
> 	- are there other tables that will need to grow as well?

are there any tables left?
most of the things that depend on MAXUSERS have died...


David Laight: