On Wed, 14 Oct 2020 10:11:23 GMT, Aleksey Shipilev <sh...@openjdk.org> wrote:
> This is fork off the SizeOf JEP, JDK-8249196. There is already the entry > point in JDK that can use the intrinsic like this: > `Instrumentation.getInstanceSize`. Therefore, we can implement the C1/C2 > intrinsic now, hook it up to `Instrumentation`, and let the tools use that > fast path today. > > With this patch, JOL is able to be close to `deepSizeOf` implementation from > SizeOf JEP. > > Example performance improvements for sizing up a custom linked list: > > Benchmark (size) Mode Cnt Score Error Units > > # Default > LinkedChainBench.linkedChain 1 avgt 5 705.835 ± 8.051 ns/op > LinkedChainBench.linkedChain 10 avgt 5 3148.874 ± 37.856 ns/op > LinkedChainBench.linkedChain 100 avgt 5 28693.256 ± 142.254 ns/op > LinkedChainBench.linkedChain 1000 avgt 5 290161.590 ± 4594.631 ns/op > > # Instrumentation attached, no intrinsics > LinkedChainBench.linkedChain 1 avgt 5 159.659 ± 19.238 ns/op > LinkedChainBench.linkedChain 10 avgt 5 717.659 ± 22.540 ns/op > LinkedChainBench.linkedChain 100 avgt 5 7739.394 ± 111.683 ns/op > LinkedChainBench.linkedChain 1000 avgt 5 80724.238 ± 2887.794 ns/op > > # Instrumentation attached, new intrinsics > LinkedChainBench.linkedChain 1 avgt 5 95.254 ± 0.808 ns/op > LinkedChainBench.linkedChain 10 avgt 5 261.564 ± 8.524 ns/op > LinkedChainBench.linkedChain 100 avgt 5 3367.192 ± 21.128 ns/op > LinkedChainBench.linkedChain 1000 avgt 5 34148.851 ± 373.080 ns/op This pull request has now been integrated. Changeset: b4d01867 Author: Aleksey Shipilev <sh...@openjdk.org> URL: https://git.openjdk.java.net/jdk/commit/b4d01867 Stats: 655 lines in 12 files changed: 655 ins; 0 del; 0 mod 8253525: Implement getInstanceSize/sizeOf intrinsics Reviewed-by: kvn, sspitsyn ------------- PR: https://git.openjdk.java.net/jdk/pull/650
