RFR(M) 8227003: [Graal] java/lang/invoke/VarHandles/VarHandleTestByteArrayAsInt.java time out

[Tom Rodriguez]

> I’d like to introduce a -XX:TieredMode=<number> flag to control this. 
> See the webrev for its description.

I think the policy you are suggesting sounds reasonable to me, but I 
find the use of a bit mask to select it to be confusing.  Several of the 
bit mask states seem invalid like TieredMode=7 seems to just be 
TieredMode=1 apart from inconsistent flags settings. How is TieredMode=1 
different from TieredStopAtLevel=1?  Isn't TieredMode=6 equivalent to 
the old -TieredCompilation?  We've disabled level 1-3 for everyone but 
JVMCI and then we've disable the special level 1 for JVMCI, so isn't 
level 4 the only thing left?

Why not have some symbolic names with a clearer description of what 
those modes are?  Do we even need/want this much flexibility exposed? 
Maybe -TieredCompilation  defaults to the new behaviour in the presence 
of +UseJVMCICompiler and a new StrictTieredCompilation gives you the old 
behaviour.

tom


> 
> To make the tests work out-of-the-box I check if the flags 
> -XX:-TieredCompilation and -XX:+UseJVMCICompiler are on the command line 
> and turn the tiered compilation back on in non-tiered emulation mode. A 
> warning is issued to alert the user to the change. This mode is also a 
> step towards being able to remove the non-tiered policy.
> 
> Webrev: http://cr.openjdk.java.net/~iveresov/8227003/webrev.00/ 
> <http://cr.openjdk.java.net/%7Eiveresov/8227003/webrev.00/>
> JBS: https://bugs.openjdk.java.net/browse/JDK-8227003
> 
> igor
> 
> 
>