[RFR] 8064716: TestHumongousShrinkHeap.java can not be run with -XX:+ExplicitGCInvokesConcurrent

Bengt Rutisson bengt.rutisson at oracle.com
Fri Nov 14 12:46:22 UTC 2014

On 2014-11-14 13:52, Andrey Zakharov wrote:
> Thanks for review, guys.
> About rotating options in nighlies is a good idea because it can reveals more product issues.
> As this flag is "normal" and it can be used within product by everyone we should test all cases with this flag too. IMHO.

I did not mean that we should stop testing with 
ExplicitGCInvokesConcurrent. I was suggesting that we should add test 
for this functionality rather than relying on the nightly testing to be 
configured the right way.

Either way that can be a separate discussion topic, so I'm fine with the 
currently proposed change.


> I'll fix comment.
> Thanks.
> ----- Original Message -----
> From: bengt.rutisson at oracle.com
> To: jesper.wilhelmsson at oracle.com, andrey.x.zakharov at oracle.com, hotspot-gc-dev at openjdk.java.net
> Sent: Friday, November 14, 2014 11:55:56 AM GMT +04:00 Abu Dhabi / Muscat
> Subject: Re: [RFR] 8064716: TestHumongousShrinkHeap.java can not be run with -XX:+ExplicitGCInvokesConcurrent
> On 2014-11-13 19:17, Jesper Wilhelmsson wrote:
>> That depends.. Will this work for all cases where
>> -XX:+ExplicitGCInvokesConcurrent is added to the command line from
>> different frameworks etc?
> Jesper, the command line flags specified in the @run tag are *appened*
> to whatever the framework passes in. So, with Andrey's change the
> -XX:-ExplicitGCInvokesConcurrent in the @run tag will always override
> any -XX:+ExplicitGCInvokesConcurrent passed in from the framework. Note
> that this is a "normal" hotspot flag (not specially treated like the GC
> selection flags) so there is not conflict in specifying the same flag
> multiple times on the command line. The rule "last one wins" applies.
> Andrey, the changes look good.
> One minor thing is that I would prefer the @run tag in
> TestHumongousShrinkHeap.java to be a single line. I think it is a bit
> hard to read when the @run tag gets split up over multiple lines:
>     30  * @run main/othervm -XX:-ExplicitGCInvokesConcurrent
> -XX:MinHeapFreeRatio=10
>     31  * -XX:MaxHeapFreeRatio=12 -XX:+UseG1GC -XX:G1HeapRegionSize=1M
> -verbose:gc
>     32  * TestHumongousShrinkHeap
> Then a general question. We need this change because we some days rotate
> in -XX:+ExplicitGCInvokesConcurrent in our nightly testing. Is that
> really a good idea? (I'm sure it was requested from the GC team at some
> point, but maybe it is time to re-evaluate that decision.) A different
> way of handling these failures would be to stop rotating in that flag in
> our testing. I am not sure it really improves our quality and apparently
> it causes issues. Maybe we should just add a few tests that explicitly
> test with -XX:+ExplicitGCInvokesConcurrent?
> Thanks,
> Bengt
>> /Jesper
>> Andrey Zakharov skrev 13/11/14 18:11:
>>> Simplest way is the preferred way to solve issues, right?
>>> On 13.11.2014 22:09, Jesper Wilhelmsson wrote:
>>>> Hi Andrey,
>>>> Is this the preferred way over using @requires?
>>>> /Jesper
>>>> Andrey Zakharov skrev 13/11/14 18:05:
>>>>> Hi, team. Excuse me for disturbing you, here is simple fix for subj.
>>>>> I've added explicit -XX:-ExplicitGCInvokesConcurrent to invocations
>>>>> Its fixes at least twu test bugs:
>>>>> https://bugs.openjdk.java.net/browse/JDK-8062957
>>>>> https://bugs.openjdk.java.net/browse/JDK-8064716
>>>>> webrev:
>>>>> http://cr.openjdk.java.net/~azakharov/8064716/webrev/
>>>>> Thanks.

More information about the hotspot-gc-dev mailing list