Ahh. Thanks for the insight, Alan.

But set_bit() et. al. will generate an incredible amount of churn;
what if I split the fields up to prevent false-sharing?

Do you feel lucky ;-)

I'd rather set_bit and friends were used. They exist largely for this
kind of reason and they also have atomic test/set methods which may in
the longer term be very useful.

Yes it is churn can't argue with that.

Alan