Frederic Konrad <fred.kon...@greensocs.com> writes:
> On 26/06/2015 17:02, Paolo Bonzini wrote:
>>
>> On 26/06/2015 16:47, fred.kon...@greensocs.com wrote:
>>> From: KONRAD Frederic <fred.kon...@greensocs.com>
>>>
>>> This removes tcg_halt_cond global variable.
>>> We need one QemuCond per virtual cpu for multithread TCG.
>>>
>>> Signed-off-by: KONRAD Frederic <fred.kon...@greensocs.com>
<snip>
>>> @@ -1068,7 +1065,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
>>> qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
>>> }
>>> }
>>> - qemu_tcg_wait_io_event();
>>> + qemu_tcg_wait_io_event(QTAILQ_FIRST(&cpus));
>> Does this work (for non-multithreaded TCG) if tcg_thread_fn is waiting
>> on the "wrong" condition variable? For example if all CPUs are idle and
>> the second CPU wakes up, qemu_tcg_wait_io_event won't be kicked out of
>> the wait.
>>
>> I think you need to have a CPUThread struct like this:
>>
>> struct CPUThread {
>> QemuThread thread;
>> QemuCond halt_cond;
>> };
>>
>> and in CPUState have a CPUThread * field instead of the thread and
>> halt_cond fields.
>>
>> Then single-threaded TCG can point all CPUStates to the same instance of
>> the struct, while multi-threaded TCG can point each CPUState to a
>> different struct.
>>
>> Paolo
>
> Hmm probably not, though we didn't pay attention to keep the non MTTCG
> working.
> (which is probably not good).
<snip>
You may want to consider push a branch up to a github mirror and
enabling travis-ci on the repo. That way you'll at least know how broken
the rest of the tree is.
I appreciate we are still at the RFC stage here but it will probably pay
off in the long run to try and avoid breaking the rest of the tree ;-)
--
Alex Bennée
