🚀 go-pugleaf

In <1995Jul14.030358.28194@taylor.infi.net>, Mark Davis <mark@taylor.infi.net>:
>Parity RAM is next to useless.  It is really a waste of valuable bits.
>The only logical approach is to use no parity, or use ECC RAM.
>Parity memory can't even detect but SOME memory errors, and can't do
>ANYTHING about it, except warn (or as pointed out, just go ahead and
>crash the system anyway).

A Unix system could do much better than just crashing the system.
If the parity error occurs in a clean page the OS could just reload
the page from the FS or swap.  If it occurs in a dirty page the OS
could kill just the affected process(es).  Only parity errors in
the OS itself should require a reboot.

ECC is much better (though it also only detects SOME memory errors)
but it is also more costly.  Parity seems to have a useful niche in
the cost/benefit tradeof.
-- 
Jim Prescott - Systems Staff	jgp@seas.rochester.edu	ur-valhalla!jgp
School of Engineering and Applied Sciences, University of Rochester, NY