Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!decwrl!sgi!wiltse@oceana.SGI.COM
From: wiltse@oceana.SGI.COM (Wiltse Carpenter)
Newsgroups: comp.sys.sgi
Subject: Re: slow windows
Summary: 4Sight priorities
Message-ID: <32865@sgi.SGI.COM>
Date: 16 May 89 02:01:11 GMT
References: <80*doelz@urz.unibas.ch>
Sender: daemon@sgi.SGI.COM
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 38

In article <80*doelz@urz.unibas.ch>, doelz@urz.unibas.ch (Reinhard Doelz) writes:
> My suggestion is that you have a look on the priorities: The news_ser process
> always got a non-ageing prio of 64 on our system (somethying beyond 3.1D on 
> a 4D/80GT). Maybe you might want to change that with a 
> npri -h40 -p... 
> command inserting the right PID.  *TAKE CARE* not to use lower numbers - 
> otherwise your system is busy doing window stuff only. 

Setting non-degrading priorities for 4Sight can have several adverse
side affects.  The basic work of 4Sight can be divided into three classes.
First, it handles window user interface functions like moving, pushing,
and popping.  Second, it is an execution environment for PostScript programs
like the round clock demo.  Third, it helps in handling multiple modes
of windows.  By `multiple modes' I mean simultaneous and independent
double buffered, color index, and rgb mode windows.  Most of the work
in handling multiple mode windows is done by the hardware, but some
setup and context switching is done in conjunction with 4Sight.

Setting a non-degrading, high priority (a low numbered argument to the
npri command) for 4Sight improves the response time for pop-up menus
and window manipulation.  However as Mr. Doelz points out, if one is
running PostScript-based applications, they will get an unfair advantage
over other processes on the system.  Considering these two factors led us
to pick the value of 64 as the fixed priority for 4Sight.

The third factor I mentioned above only comes into play when a
hardware-specific number of windows are active.  The magic numbers
are 4 for an 8-bitplane Personal Iris and 16 for all other SGI machines.
After more careful analysis (made possible through new process tracing
tools), we have concluded that the best non-degrading priority for
4Sight is no non-degrading priority at all!  If you have an 8-bitplane PI,
try this:

	npri -h0 xxxxx # where xxxxx is the pid for news_server

and see if it improves window redraw time.

	-Wiltse