RFR(XS): JDK-8030808 dtrace/hotspot/Monitors/Monitors001 fails in product builds on solaris-sparc

[David Holmes]

For the record this is okay as is.

Thanks,
David

On 6/02/2014 8:15 PM, David Holmes wrote:
> On 6/02/2014 7:32 PM, Frederic Parain wrote:
>> Hi David,
>>
>> The dtrace_waited_probe() function successfully
>> work around the tail-call optimization for some
>> time, and still works for non SPARC platforms.
>> This is why I didn't try to remove it.
>> Now, something new is breaking this code again
>> on SPARC, and this changetset just aims to fix
>> the code on SPARC without impacting other
>> platform.
>
> Okay. But might my suggestion fix the tail-call issue, and the new one?
>
>> Of course, The "Good" solution is to clearly
>> identify the issue in the SS12u1 compiler and
>> to fix it.
>
> I wonder if it will disappear with the compiler upgrade?
>
> Cheers,
> David
>
>> Fred
>>
>> On 02/06/2014 06:07 AM, David Holmes wrote:
>>> Hi Fred,
>>>
>>> On 6/02/2014 12:23 AM, Frederic Parain wrote:
>>>> Greetings,
>>>>
>>>> Please review this small fix for bug 8030808.
>>>> The bug is caused by a compiler bug preventing the
>>>> hotspot:::monitor-waited DTrace probe to be fired
>>>> on SPARC. After several failed attempts to fix
>>>> the compiler behavior with #pragma and flags, I'm
>>>> proposing this simple workaround.
>>>>
>>>> CR:
>>>> https://bugs.openjdk.java.net/browse/JDK-8030808
>>>> Webrev:
>>>> http://cr.openjdk.java.net/~fparain/8030808/webrev.00/
>>>
>>> So ... if the dtrace_waited_probe call was attempting (but failing?) to
>>> work around the tail-call optimization bug, would it not suffice to drop
>>> the call and just add a return:
>>>
>>> DTRACE_MONITOR_PROBE(waited, monitor, obj(), THREAD);
>>> // This dummy return is in place to get around dtrace bug 6254741.  Once
>>> // that's fixed we can remove it and change this back to a void method
>>> return 0;
>>>
>>> ??
>>>
>>> David
>>> -----
>>>
>>>> The fix has been tested with the dtrace/hotspot test suite
>>>> and the vm.quick testlist.
>>>>
>>>> Thanks,
>>>>
>>>> Fred
>>>>
>>