Re: Config understandings

[Ignatios Souvatzis <is%beverly.kleinbus.org@localhost>]

On Tue, Oct 17, 2000 at 08:56:48PM -0400, John Klos wrote:
> > > I rebuilt my RSAREF, OpenSSL, and OpenSSH, and startup of sshd dropped
> > > from about 60 seconds of CPU time to about 15 (comparatively, the same
> > > config on a 40 mhz 68040 Mac takes about 31 seconds).
> >
> > I didn't look at RSAREF, OpenSSL and OpenSSH myself, but apparently 
> > somebody 
> > else did.
> > 
> > It was a factor-of-10-improvement in startup time to pgp2 and sshd, when
> > I made the change.
> 
> I should've been more clear: to build all of the keys anew for the first
> time took surprisingly long when I first installed OpenSSH (more than 10
> minutes). However, after all of the keys are in place, generation of the
> 768 bit RSA key, which used to take more than 60 seconds, now only takes
> about 15.

Might be different code paths. I don't know.
What I was muttering about above is the periodically recomputed host session
key.

> 
> I really don't want all of my users to end up with "host fingerprint has
> changed!" messages, so I won't be able to time the regeneration of all of
> the keys, so I'll just say I assume it's faster.
>  
> > > In the last two weeks (up until I restarted ssh), the main sshd daemon had
> > > accumulated over 130 minutes of CPU time.
> > 
> > Yesyes. the m68020-40 ssh-1.2.26 sshd needs about 2 minutes of startup time
> > on a 50 MHz M68060, and another two minutes each time the session startup
> > key is recalculated.
> 
> If the ssh and OpenSSH code was similar enough, this would sound about
> right for the slower code.
> 
> > > Which leads me to another question: no matter how long the machine is
> > > idle, the load average never drops below 1.08 (yes, I'm running the
> > > distributed.net client).
> > 
> > Are you running xload or some similar applications? They chew up some 
> > cpu time for themselves as well as in the X server, which is not noticable
> > in todays standard Pentium or PowerPC machines, but noticable on <= 50 MHz
> > m68k.
> 
> I have nothing that rates anywhere in top running

you have top running? this would explain it.

Note that the resolution of this measurement is not every good, and worse,
something that's synchronized to the system clock can add up to 1.0 to the
load average even if it gives up the cpu after a few microseconds, or it can
not show up in the load average, even if it uses up nearly 10ms of each 10ms
period.

Regards,
        Ignatios