On Mon, Oct 05, 2020 at 04:13:13PM +0100, Will Deacon wrote: > > The failure to recognize the dependency in P0 should be considered a > > combined limitation of the memory model and herd7. It's not a simple > > mistake that can be fixed by a small rewrite of herd7; rather it's a > > deliberate choice we made based on herd7's inherent design. We > > explicitly said that control dependencies extend only to the code in the > > branches of an "if" statement; anything beyond the end of the statement > > is not considered to be dependent. > > Interesting. How does this interact with loops that are conditionally broken > out of, e.g. a relaxed cmpxchg() loop or an smp_cond_load_relaxed() call > prior to a WRITE_ONCE()? Heh -- We finesse this issue by not supporting loops at all! :-) Alan
