On Mon, 21 Oct 2024 18:18:12 GMT, Vladimir Ivanov <vaiva...@openjdk.org> wrote:
> This patch remove access to the shared variable to fix scalability issue in > the multithread environment. According to testing by the > specjvm2008::crypto.rsa the one thread performance reduced for less than 1% > while the score for the multithread run increased in ~2x. For the 2 socket > system with Xeon 8480+ numbers looks as: > - 1 thread: 643.15 for original version vs 642.54 for patched one; > - 224 threads: 22446.19 for original vs 46147.41 for patched. > > The RSABench microbenchmark reports no score changes for the 1 thread > (average for all testcases) and 2.4% improvement for the 224 threads. Is `Provider::getService` a bottleneck in real apps or is this mostly something which manifests in specjvm2008 and such benchmarks (which likely does what could be considered setup logic in the hot path)? I agree with the changes though: caching transient lookup keys seem a dubious optimization at best on modern HW/JVMs, and doing so in a way that might cause cache-line ping-pong on large systems looks pretty bad. ------------- PR Comment: https://git.openjdk.org/jdk/pull/21622#issuecomment-2427678222
