How a 40-line fix closed a 400x JVM performance gap on Linux systems
TL;DR OpenJDK replaced a procfs-based routine for ThreadMXBean.getCurrentThreadUserTime() with a clock_gettime() approach using a clockid bit trick. Benchmarks show the…
40-Line Fix Cuts Java Thread User-Time Call Latency by Up to 400×
TL;DR An OpenJDK change replaced a /proc-based user-time implementation with a clock_gettime-based approach, removing file I/O and parsing. Microbenchmarks show…