Well, I'm certainly not qualified to comment on how nvidia's drivers
work internally, but I'm going to take a guess and say that it's probably
using gettimeofday() or some other function which references the system
clock in an important timing loop. Once that's disrupted and it somehow
thinks that time is moving backwards
, it goes on the fritz and dies.
As far as I know, system clock drift doesn't happen very often on "regular"
systems though... I'm not sure how badly it affects other things, so it may
have been present and you just haven't noticed it until now. For example,
if a network adapter is affected, you might have a packet loss every now and
then, but things (the adapter, the protocol, etc.) are built robust enough so
that the packet is just resent again and you won't notice anything.
Btw, if you see the same thing after recompiling the kernel with that flag,
try using the "notsc" boot option.