[rescue] Ultra1 OBP firmware message on installation boot

[Sid Odgers]

Is this problem similar to the intel F0/0F and cyrix 'Coma' bug from
a few years back?  Or is it a Solaris bug?  I hadn't heard anything
about it, and I've got a few multi-user Ultra1s running NetBSD/64.

On Thu, Feb 13, 2003 at 03:50:03AM -0500, Curtis H. Wilbar Jr. wrote:
> Keep in mind there is an issue on Ultra-1 machines in 64 bit mode
> where a userland assembly language program can do something bad
> to the machine (I think it can halt the cpu).  This problem is
> not present when running in 32 bit mode.
> 
> This is documented out there on the web somewhere.  If users will not
> be allowed logins to the box (i.e. a web server only allowing http and
> maybe ftp) then that won't be a problem.
> 
> -- Curt
> 
> >Date: Thu, 13 Feb 2003 19:48:01 +1100
> >From: Sid Odgers <sunrescue at dysphoria.eu.org>
> >To: patrick at zill.net, The Rescue List <rescue at sunhelp.org>
> >Subject: Re: [rescue] Ultra1 OBP firmware message on installation boot
> >User-Agent: Mutt/1.4i
> >
> >Yea,
> >
> >In terms of performance, unless you're doing heavily memory bound
> >jobs (ie processes which require more than 4GB of VM) or compute
> >jobs which use 64 bit integers or floats, you'd be hard pressed
> >to notice the difference.  If you ARE, then 64 bit computation
> >will be orders of magnitude faster (1 64-bit instruction takes
> >the place of 3 or 4 32-bit instructions which emulate the
> >64-bit instructions for long double(?) and long long types),
> >and large datasets will be unusable as a 64-bit memory pointer
> >is required to use more than 4GB of VM on flat architectures (
> >and it's usually not worth the performance hit on segmented
> >architectures like the newer IA32 stuff which, from memory,
> >has a 4 bit segment offset pointer in the LDT, allowing you
> >to address more than 4GB of VM in 4GB chunks)
> >
> >Nonetheless, 64-bit mode is 'cooler', and the (minimal) performance
> >hit you take for running 64 bit code instead of 32 bit code isn't
> >going to be noticable either way on a 1/170. :)
> >
> >On Thu, Feb 13, 2003 at 02:25:53AM -0500, Patrick Giagnocavo +1.717.201.3366 
> wrote:
> >> I am loading Solaris 9 on an Ultra1/170 with OBP 3.5 .
> >> 
> >> On boot, the installer gives a message about using the 32bit OS
> >> instead of 64bit OS.
> >> 
> >> I googled and found out how to change it, but my question is, is there
> >> a performance difference between the 2 kernels?  
> >> 
> >> I will be doing some PostgreSQL and web serving and some Perl (spit).
> >> 
> >> --Patrick
> >> _______________________________________________
> >> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue
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