On Thu, Jul 16, 2020 at 09:44:27PM -0700, Eric Biggers wrote: ... > +Note that when the cmpxchg_release() fails due to another task already > +having done it, a second smp_load_acquire() is required, since we still > +need to acquire the data that the other task released. When people talk about releasing data, they usually mean something different from what you mean here (i.e., they usually mean deallocating). Likewise, acquiring data (to the extent that it means anything) would generally be regarded as meaning a simple read. I recommend changing the last phrase above to: ... since we still need a load-acquire of the data on which the other task performed a store-release. Alan Stern