Terminal paging in the kernel

[Mats Wichmann]

I have learned something from this discussion. Number one is to try harder
to keep my foot out of my mouth. I had not really meant to comment on the
topic at hand, only to respond to the comment about the disk partitions
and sizes being wired into the driver. I am now in the process of pulling
together a summary of what I have seen on this topic, this will be more
carefully thought out than my previous submission. Expect posting in a few
days (hold breath in eager anticipation....and it won't all be anti-paging).

I do have to respond to the flames I have gotten, however, because I feel
badly scorched. I worried about informing the pager about the characteristics
of the terminal. I got flames to the effect of `EVER HEARD OF TERMCAP?'. 
Okay, I have heard of termcap. I even use it. The pager is informed through
an ioctl how many lines/characters the screen will hold. Now - how is this
ioctl performed? First you have to find out what the terminal type is...
this problem has not really been solved. Notice that Berkeley used to use
ttytype (is this still the case for 4.2). Have you noticed Bell releases
with this feature in them? All UniSoft System III/V releases are also
missing this handy little feature...(although I quickly put it in for our
system). What about dialups - TSET options handle specifying the teriminal
type on login to a dialup, but not everybody supports tset either. A pager
such as more knows when output is directed to a terminal and when it isn't,
and behaves appropriately. Have you built the same knowledge into the
kernel? I presume you have, since otherwise you would have had lots of
complaints - or is every program responsible for sending out the ioctl
to stop paging (which would be a real mess).

I am not arguing against the idea of kernel paging here - just showing
my ignorance and asking a few questions that still bother me. Answers
anyone (WITHOUT the flames, this time).


	    Mats Wichmann
	    Dual Systems Corp.
	    ...{ucbvax,amd70,ihnp4,cbosgd,decwrl,fortune}!dual!mats

  It now became apparent (despite the lack of library paste)	 
  that something had happened to the vicar;	[ Edward Gorey ]