RFR(S) 8205105: VM crashes with "assert(Universe::heap()->is_in_reserved(start + words - 1)) failed: not in heap

[Igor Veresov]

Thanks, Vladimir!

igor

> On Jun 20, 2018, at 4:43 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
> 
> On 6/20/18 4:17 PM, Igor Veresov wrote:
>>> On Jun 20, 2018, at 3:43 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>>> 
>>> On 6/20/18 3:22 PM, Igor Veresov wrote:
>>>>> On Jun 20, 2018, at 3:20 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>>>>> 
>>>>> Why Graal is affected even when LOHP is not used?
>>>> LOHP is dynamically turned on by JVMTI.
>>> 
>>> Okay. In other world we can't use fast TLAB refill because JVMTI can switch on LOHP at any time. Got it.
>>> 
>> Well, unless we want to add an additional dynamic check of the LOHP state. That’s also a possible solution if we want to keep the fast TLAB refill.
> 
> Nope. We removed it from Hotspot in JDK 11. I don't think we should spend time supporting it in Graal.
> 
>>> I still did not get why GC tests which do not use LOHP still fail with Graal. And how these changes fix it?
>> Because, as Stefan noted in the bug, when Graal does fast TLAB refill it does so without setting the new _allocation_end field.
> 
> It means Graal uses fast TLAB refill by default. That is answer I was waiting for.
> 
>> The changes fix it by avoiding manually allocating TLABs in the stub (during fast TLAB refill) and calling the runtime instead.
> 
> Okay. Got it. Reviewed.
> 
> Thanks,
> Vladimir
> 
>> igor
>>> 
>>> Thanks,
>>> Vladimir
>>> 
>>>>> 
>>>>> I don't see changes which mapped new TLAB fields added by Low-Overhead Heap Profiling.
>>>>> 
>>>>> I don't see your answers to Stefan's comment in bug report about Graal's code which is not fixed for _allocation_end.
>>>>> 
>>>>> Does Graal still use fast TLAB refill as default mode?
>>>> You cannot use TLAB refill with LOHP at all.
>>>>> 
>>>>> FastTLABRefill was deprecated by 8194084: "Obsolete FastTLABRefill and remove the related code":
>>>>> 
>>>>> http://hg.openjdk.java.net/jdk/jdk/rev/9010e596f391
>>>>> 
>>>>> Should we remove it from Graal too?
>>>>> 
>>>> Not for JDKs <11.
>>>> igor
>>>>> Thanks,
>>>>> Vladimir
>>>>> 
>>>>> On 6/20/18 2:47 PM, Igor Veresov wrote:
>>>>>> Low-Overhead Heap Profiling is not compatible with fast TLAB refill. It needs to be disabled.
>>>>>> Webrev: http://cr.openjdk.java.net/~iveresov/8205105/webrev/
>>>>>> Thanks,
>>>>>> igor