[aarch64-port-dev ] RFR: 8243339: AArch64: Obsolete UseBarriersForVolatile option

[Xiaohong Gong]

Hi Andrew,

Thanks for having a look at it!
 
 > On 5/14/20 10:37 AM, Andrew Haley wrote:
 > > On 5/14/20 9:48 AM, Andrew Dinn wrote:
 > >> Just for references a direct link to the webrev, issue and CSR
 > are:
 > >>
 > >>   https://cr.openjdk.java.net/~xgong/rfr/8243339/webrev.00/
 > >>   https://bugs.openjdk.java.net/browse/JDK-8243339
 > >>   https://bugs.openjdk.java.net/browse/JDK-8243456
 > >>
 > >> The webrev looks fine to me. Nice work, thank you!
 > >
 > > There's a problem with C1: we generate unnecessary DMBs if we're
 > using
 > > TieredStopAtLevel=1 or if we only have the client compiler. This
 > is a
 > > performance regression, so I reject this patch.
 > 
 > There are similar regressoins in the interpreter.

Yes, I agree with you that regressions exist for interpreter and client compiler. 
So do you think if it's better to add the conditions to add DMBs for C1 and interpreter? 
How about just excluding the scenario like "interpreter only", "client compiler only" and "TieredStopAtLevel=1" ?

Thanks,
Xiaohong Gong