🚀 go-pugleaf

In article <45180@bbn.COM> dswartz@BBN.COM (Dan Swartzendruber) writes:
>Although it is possible to construct a
>theoretical scenario where an instruction restart CPU could get into an
>infinite page-fault loop, I will respectfully suggest that if your system
>only has 6 free pages of memory, the effective result (as far as getting
>any useful work done is concerned) will be pretty much the same!

Somebody else also gave the example:

	movw	$300, $100

(obviously a VAX 8-)).  Dan is, I think, following up to the comment that,
if you're tight on free memory, swapping the page with $100 could cause the
page with $300 to be swapped out (and vice-versa), which would cause real
problems with instruction restart.

Now, my point:  how about shared memory?  (SysV-type shared memory, not
multi-processor-type shared memory.)  With instruction restart, the value in
$300 could have changed, while, with instruction continuation, it doesn't
matter.  How do various OS's and hardwares handle it?

-- 
Sean Eric Fagan  | "Time has little to do with infinity and jelly donuts."
seanf@sco.UUCP   |    -- Thomas Magnum (Tom Selleck), _Magnum, P.I._
(408) 458-1422   | Any opinions expressed are my own, not my employers'.