On Mon, Nov 14, 2022 at 5:12 PM Paul Ruizendaal <pnr(a)planet.nl> wrote:
Following on from the exchange on TUHS about DG-UX, it
would seem to me
that the (Unix) unified cache was invented at least three times for Unix:
Not to quibble too much, but s/cache/memory/ I think is a fairer way of
saying that.
- John Reiser at AT&T
- At Sun
- At DG
- At CMU (Mach)
The interesting thing again, is that while they while all of these
implementations seem to have been technologically 'better' - only Mach
lived on from the original developers. And in the case of Mach, by the
time it was mainstream (macOS) the original implementation had been
replaced a few times - so while the concepts are there, I don't think much
of the Original CMU code is left in XNU/Darwin [or for that matter in the
OSF flavors -- Tru64 rewrote it but it died and the OSF/RI kernel never
went anywhere either].
As I said, the lesson to TUHS -- as much as I'm a techie and I am
interested in the 'proper' way of doing things ... "good enough" is
often
what rules.
It's too bad none of the good memory implementations made it into
>systems<< that lasted.
Clem
ᐧ