On 2013-01-23, at 1:14 AM, Vitaly Davidovich <vita...@gmail.com> wrote:
> Personally, optimizing for interpreter (or even C1) doesn't seem worth it. > If something's truly hot and best perf is desired then use C2 or tiered. If > the method isn't hot enough to trigger the C2 threshold, then why bother? > You're already behind the 8 ball in terms of performance. Maybe this is > heresy though :). > > Maybe, maybe not.. what I can say is this is a case of an optimization that doesn't scale down. In cases where scale down was needed I have recommended to customers that they "flash" their system just to push the counter beyond the compile threshold. In those cases naively compiled code was still a lot better than interrupting byte code. I've also turned off decay in a number of applications where loads weren't quite enough to beat the decay behaviour. Yeah I know this is at the risk of filling code cache but code cache occupancy is something that I regularly recommend people monitor for (check my VisualVM memory pool plug-in). In fact, I just tuned an app where I used -Xcomp to estimate how big the code cache needed to be to avoid filling it. Production settings had decay turned off. So, I can't say your wrong and I generally don't like fiddling with these setting but I will if I have to and I've had to in a number of instances where ensuring a compile beat leaving it alone. Regards, Kirk
