Re: [PATCH] memory: transaction API

[Ferry Huberts <mailings@hupie.com>]

On 07/21/2011 02:46 PM, Avi Kivity wrote:
> On 07/21/2011 03:26 PM, Ferry Huberts wrote:
>> >>  >   +void memory_region_transaction_begin(void)
>> >>  >   +{
>> >>  >   +    ++memory_region_transaction_depth;
>> >>  >   +}
>> >>  >   +
>> >>
>> >>  wouldn't you rather keep it safe by doing either here
>> >>
>> >>  if (!memory_region_transaction_depth)
>> >>     memory_region_transaction_depth++;
>> >>
>> >
>> >  Why? I want to allow nesting transactions (not that I anticipate
>> such a
>> >  case).
>> >
>>
>> doesn't memory_region_update_topology commit all accumulated changes?
> 
> It does.
> 
>>   if
>> it does then memory_region_transaction_depth is left non-zero in the
>> nesting case while no more changes are actually present, resulting in
>> superfluous calls to memory_region_update_topology.
>>
>> maybe I misunderstood memory_region_update_topology?
>>
> 
> update_mapping()
> {
> m_r_t_begin();
> // call memory API functions to change hierarchy
> some_other_function() entered
>   m_r_t_begin();
>   // call more memory API functions to change hierarchy
>   m_r_t_commit();  // nothing happens
> some_other_function() exits
> // call even more memory API functions to change hierarchy
> m_r_t_commit();  // all accumulated changes become visible
> }
> 

ahhh. I completely read over the memory_region_update_topology change.
shame on me, sorry for the confusion!

-- 
Ferry Huberts