Review Request: 6896043: Zero fixes

[Vladimir Kozlov]

Looks good.

Vladimir

Gary Benson wrote:
> Cool.  I've rolled the changes we've discussed into this webrev:
> 
>   http://cr.openjdk.java.net/~gbenson/zero-update-02-hs/
> 
> Let me know what you think.
> 
> Cheers,
> Gary
> 
> Vladimir Kozlov wrote:
>> I would keep thread check.
>>
>> Vladimir
>>
>> Gary Benson wrote:
>>> Vladimir Kozlov wrote:
>>>> Gary Benson wrote:
>>>>> Vladimir Kozlov wrote:
>>>>>> hotspot/src/share/vm/runtime/os.hpp:
>>>>>> Can you explain why your changes is not the same as the comment
>>>>>> says?: ((_mem_serialize_page ^ addr) & -pagesize) == 0
>>>>> Basically because I didn't know if I'd need to make changes
>>>>> anywhere else, and I didn't want to break the other platforms.
>>>>> Should I change it to what the comment says?
>>>> I am concern about correctness of your code - page sizes could
>>>> be different.  I would prefer if your code will be similar to
>>>> one in is_poll_address().
>>> So something like this:
>>>
>>>   static bool is_memory_serialize_page(JavaThread *thread, address addr) {
>>>     if (UseMembar) return false;
>>>     if (thread == NULL) return false;
>>>     return addr >= _mem_serialize_page && addr < (_mem_serialize_page + os::vm_page_size());
>>>   }
>>>
>>> The "if (thread == NULL) return false;" would no longer be
>>> necessary, so it could either be retained to preserve the old
>>> behaviour or not.  Which would you prefer?
>>>
>>> Cheers,
>>> Gary
>