Paolo Bonzini <pbonz...@redhat.com> writes:
> On 05/04/2017 15:25, Alex Bennée wrote:
>> +{
>> + int64_t executed = cpu_get_icount_executed(cpu);
>> + cpu->icount_budget -= executed;
>> + atomic_add(&timers_state.qemu_icount, executed);
>> +}
>
> Since there's only one writer, it's also okay to do
>
> atomic_set(&timers_state.qemu_icount,
> atomic_read(&timers_state.qemu_icount) + executed);
>
> (also not just faster, but also simpler to turn into TCG code if we do
> the update in gen_io_start).
OK fair enough. Annoyingly I've just noticed this breaks for 32 bit
hosts because we might not have CONFIG_ATOMIC64. What's the best
approach? #ifdef and handwave?
--
Alex Bennée
