How and When You Should Measure CPU Overhead of eBPF Programs Bryce Kahle, Datadog October 28, 2020 Why should I profile eBPF programs? CI variance tracking Tools kernel.bpf_stats_enabled kernel bpf_stats_enabled sysctl – Added in kernel v5.1 (off by default) – Turns on stats collection for all eBPF programs – exposes total run_time_ns and run_cnt – Use cases: – Benchmarking + CI/CD – Sampling profiler results in go benchmark format Can be used with benchstat and other tools kprobe runtime comparison programs no-helper add helper call benchmark program and results Thank you!

. . . . . . . . . . . . . . . . . . . . 230 8 Apache HTTP Server and Supporting Programs 235 8.1 Server and Supporting Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 . 266 8.13 suexec - Switch user before executing external programs . . . . . . . . . . . . . . . . . . . . . . . 268 8.14 Other Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INCLUDES filter in MOD INCLUDE. The module MOD EXT FILTER allows external programs to act as filters in much the same way that CGI programs can act as handlers. Multilanguage Error Responses Error response messages

. . . . . . . . . . . . . . . . . . . . 259 8 Apache HTTP Server and Supporting Programs 263 8.1 Server and Supporting Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 . 298 8.15 suexec - Switch user before executing external programs . . . . . . . . . . . . . . . . . . . . . . . 300 8.16 Other Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INCLUDES filter in MOD INCLUDE. The module MOD EXT FILTER allows external programs to act as filters in much the same way that CGI programs can act as handlers. Multilanguage Error Responses Error response messages

. . . . . . . . . . . . . . . . . . . . 272 8 Apache HTTP Server and Supporting Programs 277 8.1 Server and Supporting Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 . 316 8.18 suexec - Switch user before executing external programs . . . . . . . . . . . . . . . . . . . . . . . 317 8.19 Other Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . but is now fully supported. Asynchronous support Better support for asynchronous read/write for supporting MPMs and platforms. Per-module and per-directory LogLevel configuration The LOGLEVEL can now be

. . . . . . . . . . . . . . . . . . . . 272 8 Apache HTTP Server and Supporting Programs 277 8.1 Server and Supporting Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 . 316 8.18 suexec - Switch user before executing external programs . . . . . . . . . . . . . . . . . . . . . . . 317 8.19 Other Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . but is now fully supported. Asynchronous support Better support for asynchronous read/write for supporting MPMs and platforms. Per-module and per-directory LogLevel configuration The LOGLEVEL can now be

. . . . . . . . . . . . . . . . . . . . 295 8 Apache HTTP Server and Supporting Programs 299 8.1 Server and Supporting Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 . 339 8.18 suexec - Switch user before executing external programs . . . . . . . . . . . . . . . . . . . . . . . 340 8.19 Other Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . but is now fully supported. Asynchronous support Better support for asynchronous read/write for supporting MPMs and platforms. Per-module and per-directory LogLevel configuration The LOGLEVEL can now be

. . . . . . . . . . . . . . . . . . . . 295 8 Apache HTTP Server and Supporting Programs 299 8.1 Server and Supporting Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 . 339 8.18 suexec - Switch user before executing external programs . . . . . . . . . . . . . . . . . . . . . . . 340 8.19 Other Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . but is now fully supported. Asynchronous support Better support for asynchronous read/write for supporting MPMs and platforms. Per-module and per-directory LogLevel configuration The LOGLEVEL can now be

acquisition professionals with details on how to adopt Agile practices within each element of their programs, thus helping them to succeed in an increasingly complex environment. Agile has emerged as the programmatic risk, and respond to feedback and changes more quickly than traditional methods. Programs can adopt Agile practices within current policy by tailoring program processes and structure to principles of Agile development specifically to the DoD context. More and more federal acquisition programs have begun to integrate aspects of Agile development into their strategy. Yet the DoD has not

- No modifications of the tracee rbperf rbperf - Profile Ruby programs rbperf - Profile Ruby programs - Trace complex Ruby programs execution rbperf – on-CPU profiling - $ rbperf record --pid=124 the stack walking for a dynamic language - Supporting multiple Ruby versions Challenges - Implementing the stack walking for a dynamic language - Supporting multiple Ruby versions - Correctness testing testing Challenges - Implementing the stack walking for a dynamic language - Supporting multiple Ruby versions - Correctness testing - BPF safety features Future plans - Integrate in Facebook’s profiling

connectivity and IP address management is managed by the non-Cilium CNI plugin, but Cilium attaches BPF programs to the network devices created by the non-Cilium plugin to provide L3/L4/L7 network visibility & (IPAM) via ENI. After the initial networking is setup, the Cilium CNI plugin is called to attach BPF programs to the network devices set up by aws-cni to enforce network policies, perform load-balancing, and allocation (IPAM). After the initial networking is setup, the Cilium CNI plugin is called to attach BPF programs to the network devices set up by Azure CNI to enforce network policies, perform load-balancing,