That's excellent to know... I wasn't aware that this was being looked at.  Something that's been in the back of my mind for a while is trying to measure JIT performance vs. JIT code cache size, architecture being run on, and workload.  As I understand it, the JIT code cache is a fixed size (~1meg iirc) which doesn't make a lot of sense to me given the variance in CPU cache size (generally in the range of 512k-4m depending on whether you're running on Intel/AMD/ARM, desktop/server, low/high end, HT enabled/disabled, and oddball/extreme CPU configurations like the Intel 5775C with it's 128meg LLC) and then there's the cost of potentially thrashing the JIT cache vs maintaining a larger cache despite the fact that it might exceed the capacity of the CPU cache. (However to measure this I think a few new VM params would be needed: a r/w JIT cache size, JIT cache code evictions (since last full gc?), JIT cache code additions (since last full gc?), Avg cache code size... the current machine code method/compaction counts are a good start but a bit coarse). Just thought I'd throw this out there since it seemed apropos...

Thanks,

Phil