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by x0x0 3949 days ago
I think I disagree about the observability -- vtune is a lot easier to use when just tuning straight C++ rather than java
2 comments

Are you familiar with JMH's perfasm? http://psy-lob-saw.blogspot.com/2015/07/jmh-perfasm.html

And for profiling apps on production, I've yet to encounter a more thorough, low-overhead profiler than Java Flight Recorder.

no but i'll check it out this afternoon. Thanks!
VTune is not too dissimilar to JProfiler.

And as pron mentioned plenty of tools exist for lower level access.

Vtune gives access to PMU counters as well as attributing them to assembly. JProfiler is a purely java level profiler (it won't even tell you Hotspots in the JVM itself, nevermind assembly). They're not really comparable.
jprofiler, at least for my use cases, isn't really similar to vtune at all. I know what my hot spots are: it's the inner bits of algorithms that run a few billion to a few trillion times. What I need to do is understand, as granularly as possible, the exact instructions and how the various caches and memory are operating. Convex and tree optimizers are generally memory speed limited and my goal is to have this code run at eg 0.9+ of memory b/w speed.