Re: [PATCH] Don't call cpu_synchronize_state() in apic_init_reset()

[Avi Kivity <avi@redhat.com>]

On 09/23/2009 06:07 PM, Jan Kiszka wrote:
> Avi Kivity wrote:
>    
>> On 09/22/2009 05:51 PM, Gleb Natapov wrote:
>>      
>>> Each caller of the function already calls it.
>>>
>>> Signed-off-by: Gleb Natapov<gleb@redhat.com>
>>> ---
>>>    hw/apic.c |    1 -
>>>    1 files changed, 0 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/hw/apic.c b/hw/apic.c
>>> index 3a2e128..a9d1fb8 100644
>>> --- a/hw/apic.c
>>> +++ b/hw/apic.c
>>> @@ -488,7 +488,6 @@ void apic_init_reset(CPUState *env)
>>>        if (!s)
>>>            return;
>>>
>>> -    cpu_synchronize_state(env);
>>>        s->tpr = 0;
>>>        s->spurious_vec = 0xff;
>>>        s->log_dest = 0;
>>>
>>>        
>> Still, it's safer to live this in.
>>
>>      
> Yet another diff to upstream...
>
> It's really time to stabilize this still a bit fuzzy register sync
> model, also in qemu-kvm. If you think we need it, let us push it
> upstream - with a sound explanation, and maybe even with more sync
> points for the sake of consistency.
>
>    

Functions calling each other in the same subsystem can rely on callers 
calling cpu_synchronize_state().  Across subsystems, that's another 
matter, exported functions should try not to rely on implementation 
details of their callers.

(You might argue that the apic is not separate subsystem wrt an x86 cpu, 
and I'm not sure I have a counterargument)

-- 
error compiling committee.c: too many arguments to function