[13] RFR(S): 8226536: Catch OOM from deopt that fails rematerializing objects

[Nils Eliasson]

Doesn't that only work on classes loaded by the Bootstrap classloader?

// Nils

On 2019-07-05 12:00, Vladimir Ivanov wrote:
> test/hotspot/jtreg/vmTestbase/nsk/share/gc/gp/GarbageUtils.java:
>
> +          * It is Important that the impl is not inlined.
>
> What do you think about putting @DontInline on eatMemoryImpl to 
> guarantee that invariant?
>
> Best regards,
> Vladimir Ivanov
>
> On 04/07/2019 16:27, Nils Eliasson wrote:
>> Hi,
>>
>> This is a patch of GarbageUtils.java used by a bunch of GC tests.
>>
>> This issue was diagnosed by Stefan Karlsson and passed to the 
>> compiler team.
>>
>> The core problem is that the test relies on successfully catching OOM 
>> errors. But the OOM causes a deopt, and the deopt must rematerialize 
>> some objects before passing the execution on to the interpreter to 
>> run the catch-block. If the rematerialization can't allocate, it will 
>> pass the OOM on, without having run the catch-block.
>>
>> With this patch I fix the tests by wrapping the faulting code with an 
>> extra layer of try-catch-OOM. It relies on not inlining the inner 
>> method, because then it would be part of the compiled frame being 
>> deoptimized.
>>
>> In general this is a problem for any kind of deopt when we are out of 
>> heap. Another bug will be opened to keep tracking this issue.
>>
>> Webrev:http://cr.openjdk.java.net/~neliasso/8226536/webrev.02/ 
>> <http://cr.openjdk.java.net/~neliasso/8226536/webrev.02/>
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8226536
>>
>> // Nils
>>