Re: Virtual Memory

[hyc@locus.com (Howard Chu)]

  >>>>> "Stephan" == Stephan Haslbeck <haslbecs@informatik.tu-muenchen.de> writ
 es:
  Stephan> And what if the space is blocked by another program that
  Stephan> won't stop for a long time (or never)? Only programs that are
  Stephan> expected to exit quickly after their start can run under such
  Stephan> conditions. I think there would be more restrictions than
  Stephan> without any VM.

  You could do the swapping on context-shift. Remember the kernel has
  control at frequent intervals.
...
  In fact, I think that most UNIX still uses swapping as well as paging.

Well, it was really quite rare for any swapping system I worked with to
actually have any processes swapped out. And these days, it's all demand-
paging anyway, you never really just arbitrarily remove an entire process
from memory, you only do things one page at a time...
  -- Howard