Re: real kernel bloat

Mike McLagan (msmith@quix.robins.af.mil)
Tue, 25 Jun 1996 09:50:47 -0400 (EDT)


> I recently got a DEC AlphaStation at my new job. It's running Digital
> UNIX, since that's what the other machines I am charged with maintaining
> run.
>
> As far as I can tell Digital UNIX (formerly Digital OSF/1) is a fat
> bloated pig. At boot the kernel allocates over 8 megabytes of memory to

It IS a large kernel. I don't see why you are surprised. Solaris,
HPUX, etc. I could go on and on, are just as fat.

> itself on a 32 meg machine. Once I load up X and my assortment of
> desktop doodads the machine runs acceptably, as long as only one thing
> is running. If, however, I try to compile something and then do
> something else the machine swaps like mad, and simple window system
> operations like raising or moving windows have 5-10 second delays
> between pressing the buttons and seeing something happen.
>
> I compare this with my home Linux system, with 486-DX2/66 instead of a
> 233 MHz Alpha, but also with 32M of memory. Even though I've got enough
> going to have pushed this machine a little ways into swap, it never
> feels as loaded as the Digital UNIX box. And the kernel takes no more
> than 1.5M of memory once loaded. Despite the AlphaStation having a
> processor that's at least 5 times faster and having PCI instead of ISA
> for its peripherals, Digital UNIX manages to make it suck for
> interactive performance.

My experience with Alpha has been exactly opposite.

> So those of you complaining about Linux's kernel bloat haven't seen
> anything if you haven't seen Digital UNIX. Linux has a long, long way
> to go before it could aspire to be that bloated.

Linux also as a long way to go before it matches Digital UNIX period.
I am a pro-Linux man, but Linux still hasn't matured in quite a few
areas, which we all know, and no-one is bashing. I just try to help
the maturity take place faster.

Our AlphaServer supports 5 programmers on X, runs Oracle database server,
Web database interface, DNS, Samba services, sendmail and POP3 for
the whole office. Also includes a true robust pthreads interface,
logical volume manager, STREAMS, reliable signals, real-time support,
solid scaleable SMP, solid clustering technology, good security features.
It will be a LONG time before Linux matches DECs clustering technology,
that is due to the fact that they are pioneers in the field and have
about a 20 year head start.

All the while, the interactive performance stays good.

I would love to drop in Linux for this but it isn't up to it yet.
I AM excited that Linux-AXP promises to be a lot smaller than DEC
UNIX when it eventually reaches DECs capability and stability.

Try to be a little LESS obviously biased when comparing other
poor helpless UNIX flavors, hey all of us want Linux to take over
but don't kid yourself into thinking it already has.

Melvin S.