Phase-aware System-Side Sampling for HPC.

HPC compute centers always benefit from better insights into the application mix running on their systems. We present a low-overhead statistical sampling tool running in the background on the system side, which can capture application compute phases. Our tool leverages eBPF (extended Berkeley Packet Filter) from modern Linux kernels to extract phase information provided by developers via instrumentation or instruction pointers. We outline how this tool can be integrated into the monitoring framework DCDB, and we show resulting performance insights.