[Qemu-devel] Re: [PATCH] fix smp with tcg mode and --enable-io-thread

[Jan Kiszka]

Jan Kiszka wrote:
> Marcelo Tosatti wrote:
>> On Mon, Jun 21, 2010 at 10:58:32PM +0200, Jan Kiszka wrote:
>>> Jan Kiszka wrote:
>>>> Marcelo Tosatti wrote:
>>>>> Clear exit_request when iothread grabs the global lock. 
>>>>>
>>>>> Signed-off-by: Marcelo Tosatti <address@hidden>
>>>>>
>>>>> diff --git a/cpu-exec.c b/cpu-exec.c
>>>>> index 026980a..74cb973 100644
>>>>> --- a/cpu-exec.c
>>>>> +++ b/cpu-exec.c
>>>>> @@ -236,10 +236,8 @@ int cpu_exec(CPUState *env1)
>>>>>      asm("");
>>>>>      env = env1;
>>>>>  
>>>>> -    if (exit_request) {
>>>>> +    if (exit_request)
>>>>>          env->exit_request = 1;
>>>>> -        exit_request = 0;
>>>>> -    }
>>>> Coding style...
>>>>
>>>>>  
>>>>>  #if defined(TARGET_I386)
>>>>>      if (!kvm_enabled()) {
>>>>> diff --git a/cpus.c b/cpus.c
>>>>> index fcd0f09..ef1ab22 100644
>>>>> --- a/cpus.c
>>>>> +++ b/cpus.c
>>>>> @@ -598,6 +598,7 @@ void qemu_mutex_lock_iothread(void)
>>>>>          }
>>>>>          qemu_mutex_unlock(&qemu_fair_mutex);
>>>>>      }
>>>>> +   exit_request = 0;
>>>>>  }
>>>>>  
>>>>>  void qemu_mutex_unlock_iothread(void)
>>>>>
>>>>>
>>>> I looked into this a bit as well, and that's what I also have in my
>>>> queue.
>>>>
>>>> But things are still widely broken: pause_all_vcpus and run_on_cpu as
>>>> there is no guarantee that all VCPUs regularly call into
>>>> qemu_wait_io_event. Also breakpoints don't work, not only in SMP mode.
>> This fixes pause for me:
>>
> 
> Partially. It caused regressions on the SMP scheduling without the early
> loop exit in my patch. I will break up my changes later today and post
> them as series.

After fixing the APIC/IOAPIC fallouts, the series is almost done.
Unfortunately, host&guest debugging is totally broken for
CONFIG_IOTHREAD (I also noticed that [1] is still not merged). I will
try to fix this first as it may require some more refactorings.

Jan

[1] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/52718

signature.asc
Description: OpenPGP digital signature