Pagable Kernels (was: Re: Kernel Definition)

[John F Haugh II]

In article <1991May29.201432.1803695 at locus.com> richard at locus.com (Richard M. Mathews) writes:
>You better hunt out each place where such assumptions are made, and
>either temporarily pin down the pages you need or get a lock for the
>appropiate resource.  And then you better think about deadlock and
>performance implications of keeping things pinned or locked.

Note that the AIX v3 kernel is both pagable and pre-emptable, so you
have the problems even if you pin the pages in memory.  It is quite
fun to discover that the resource you just fondled is at this very
moment being altered by another process thread.  All of the usual
assumptions about "atomic" operations go straight out the window in
this case.
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