12 RFR(XS) 8214329: SwingMark SubMenus 9% regression in 12-b19 on Linux client

[dean.long at oracle.com]

On 12/18/18 7:12 AM, Sean Mullan wrote:
> Looks good, although I think someone from the HotSpot Group should 
> also review it.
>

Thanks Sean.  Tobias reviewed it.

> On the bug, can you add the details below into the Description?

Sure.

> Also, since you have no regression test, you will need a noreg label 
> (I guess noreg-perf would be appropriate). 

OK, thanks.

> Also, the bug says it is BlockedBy JDK-8215205 which should probably 
> be removed.
>

That's because JDK-8215205 hasn't been pushed yet.

dl

> Thanks,
> Sean
>
> On 12/17/18 5:49 PM, dean.long at oracle.com wrote:
>> https://bugs.openjdk.java.net/browse/JDK-8214329
>> http://cr.openjdk.java.net/~dlong/8214329/webrev/
>>
>> In "8212605: Pure-Java implementation of 
>> AccessController.doPrivileged", the stackwalk in 
>> JVM_GetStackAccessControlContext was changed from using a 
>> vframeStream to using a javaVFrame, so that it could access locals. 
>> However this caused a regression because javaVFrame has more 
>> overhead. JDK-8215205 fixes the problem by allowing the use of 
>> javaVFrame only when needed.
>>
>> This change reverts JVM_GetStackAccessControlContext back to using 
>> vframeStream, and uses the new API in JDK-8215205 to get a javaVFrame 
>> lazily.  It also removes two unnecessary calls to java_sender().
>>
>> dl