On 02/11/2017 12:24, Pavel Dovgalyuk wrote: >> I am not sure about this. I think if instead you should return false >> from here and EXCP_INTERRUPT from cpu_exec. > The problem is inside the TB. It checks cpu->icount_decr.u16.high which is -1. > And we have to enter the TB to cause an exception (because it exists in > replay log). > That is why we reset this flag and try to execute the TB.
But if u16.high is -1, shouldn't you return EXCP_INTERRUPT first (via "Finally, check if we need to exit to the main loop" in cpu_handle_interrupt)? Then only cause the exception when that one is processed. Paolo >> More important: there is still a race, because high can be set to -1 >> right after your atomic_set. > I'm not sure about it. But even the race exists, exec_nocache attempt will be > repeated > after failed try. > > Returning true is ok here, because we know that exception will happen > (because it is > recorded in the log).
