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References: <87h9cfdlcd.fsf@linaro.org> <5773E339.6020702@gmail.com>
From: Alex =?utf-8?Q?Benn=C3=A9e?= <alex.bennee@linaro.org>
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Date: Wed, 29 Jun 2016 17:09:29 +0100
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Subject: Re: [Qemu-devel] [RFC 7/8] cpu-exec-common: Introduce
 async_safe_run_on_cpu()
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To: Sergey Fedorov <serge.fdrv@gmail.com>
Cc: Sergey Fedorov <sergey.fedorov@linaro.org>, qemu-devel@nongnu.org, Riku Voipio <riku.voipio@iki.fi>, Peter Crosthwaite <crosthwaite.peter@gmail.com>, patches@linaro.org, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <rth@twiddle.net>


Sergey Fedorov <serge.fdrv@gmail.com> writes:

> On 27/06/16 12:36, Alex Bennée wrote:
>> Sergey Fedorov <sergey.fedorov@linaro.org> writes:
>>
>>> From: Sergey Fedorov <serge.fdrv@gmail.com>
>>>
> (snip)
>>> diff --git a/cpus.c b/cpus.c
>>> index 98f60f6f98f5..bb6bd8615cfc 100644
>>> --- a/cpus.c
>>> +++ b/cpus.c
>>> @@ -932,6 +932,18 @@ static void qemu_tcg_destroy_vcpu(CPUState *cpu)
>>>  {
>>>  }
>>>
>>> +static void tcg_cpu_exec_start(CPUState *cpu)
>>> +{
>>> +    tcg_pending_cpus++;
>>> +}
>>> +
>>> +static void tcg_cpu_exec_end(CPUState *cpu)
>>> +{
>>> +    if (--tcg_pending_cpus) {
>>> +        signal_cpu_work();
>>> +    }
>>> +}
>> Don't these need to be atomic?
>
> 'tcg_pending_cpus' is protected by BQL.

A quick comment above the function would help then.

>
>>
>>> +
>>>  static void qemu_wait_io_event_common(CPUState *cpu)
>>>  {
>>>      if (cpu->stop) {
>>>
> (snip)
>
> Thanks,
> Sergey


--
Alex Bennée