Discussion: 8172978: Remove Interpreter TOS optimization (original) (raw)

Aleksey Shipilev shade at redhat.com
Tue Feb 28 15:14:03 UTC 2017

On 02/28/2017 04:00 PM, Doerr, Martin wrote:

I've ran jvm98 with -Xint on several PPC64 machines and on a recent s390x machine.

Surprisingly, disabling of the Tos optimization does not hurt on older hardware (Power 5 and 6). Seems like some sub benchmarks don't suffer at all or even benefit. But it really hurts on recent Power 8.

I don't think it makes sense to run performance tests with -Xint alone. Of course removing interpreter optimizations would affect interpreter performance. The real question one should ask if turning off an interpreter optimization affects peak performance and time-to-performance when compilers are enabled.

That's because in 2017 we should not expect that users who need performance would run with interpreter only. And removing complexity from interpreter without sacrificing the performance in tiered/compiled mode is certainly a plus in my book.

Thanks, -Aleksey

More information about the hotspot-dev mailing list