Subject: Re: HEADS UP: migration to fully dynamic linked "base" system
To: None <>
From: Thor Lancelot Simon <>
List: current-users
Date: 08/26/2002 11:37:42
On Mon, Aug 26, 2002 at 04:13:25PM +0100, David Laight wrote:
> On Mon, Aug 26, 2002 at 04:20:39PM +1000, Luke Mewburn wrote:
> > 
> > I will be switching NetBSD-current to have dynamically linked programs
> > in /bin and /sbin in the next day or so.
> The only problem I see is that a lot of scripts will start running
> significantly slower if the small 'workhorse' programs (ln, rm, chmod,
> test, mkdir, expr etc) become dynamic.
> Some tests I've just done indicate that the time to exec a dynamically
> linked program is about 7 times that of a static one (on i386).
> (the 3.75% improvement I've made is insignificant...)

This *is* a big deal.  It was one of the major reasons SGI faced a mass
exodus of customers in the early Irix 6 era: their systems took far longer
to start up than they ever had before, and sundry trivial shell-script
tasks (their nice GUI does tend to call a certain number of scripts) 
similarly got much slower, leading to a general perception that their OS
was becoming horribly bloated and slow when in fact many kernel operations
were faster.

The cause?  You guessed it: dynamically linking everything.  Eventually
they kind-of addressed this with a very good prebinding implementation,
but I don't see that on the short-term horizon for NetBSD.

A certain number of 'workhorse' commands, as David suggests, should remain
static so that we don't destroy shell script performance.

 Thor Lancelot Simon	                            
   But as he knew no bad language, he had called him all the names of common
 objects that he could think of, and had screamed: "You lamp!  You towel!  You
 plate!" and so on.              --Sigmund Freud