Review request 8153912: StackFrame::getFileName and StackFrame::getLineNumber not needed

[Claes Redestad]

On 2017-03-13 16:56, Mandy Chung wrote:
>
>> On Mar 12, 2017, at 9:25 PM, Ralph Goers <ralph.goers at dslextreme.com> wrote:
>>
>> 1. Walking the Throwable StackTraceElements is significantly faster in Java 8 than Java 9. I am not sure what benchmark Brent used but my results differ.
>
> I’ll be surprised if jdk 9 Throwable is slower than jdk 8 as JDK-8150778 should give some improvement.
>
> We will look into it.

I've verified this on my machine, although the difference is smaller 
when comparing 8 and 9 on the benchmarks that run on both (~10%).

Quick profiling indicates that we're spending time in 
StringTable::lookup_shared in 9, which could be due to changes in 
https://bugs.openjdk.java.net/browse/JDK-8015086

I'm currently evaluating if the performance fix suggested by Ioi has an 
effect: https://bugs.openjdk.java.net/browse/JDK-8175863

If so, this might be something we need to escalate.

/Claes