run_time_ns is a useful stats for BPF programs. However, it is gated by sysctl kernel.bpf_stats_enabled. When multiple user space tools are toggling kernl.bpf_stats_enabled at the same time, they may confuse each other. Solve this problem with a new BPF command BPF_ENABLE_STATS. Changes v7 => v8: 1. Change name BPF_STATS_RUNTIME_CNT => BPF_STATS_RUN_TIME (Alexei). 2. Add CHECK_ATTR to bpf_enable_stats() (Alexei). 3. Rebase (Andrii). 4. Simplfy the selftest (Alexei). Changes v6 => v7: 1. Add test to verify run_cnt matches count measured by the program. Changes v5 => v6: 1. Simplify test program (Yonghong). 2. Rebase (with some conflicts). Changes v4 => v5: 1. Use memset to zero bpf_attr in bpf_enable_stats() (Andrii). Changes v3 => v4: 1. Add libbpf support and selftest; 2. Avoid cleaning trailing space. Changes v2 => v3: 1. Rename the command to BPF_ENABLE_STATS, and make it extendible. 2. fix commit log; 3. remove unnecessary headers. Song Liu (3): bpf: sharing bpf runtime stats with BPF_ENABLE_STATS libbpf: add support for command BPF_ENABLE_STATS bpf: add selftest for BPF_ENABLE_STATS include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 11 ++++ kernel/bpf/syscall.c | 57 +++++++++++++++++++ kernel/sysctl.c | 36 +++++++++++- tools/include/uapi/linux/bpf.h | 11 ++++ tools/lib/bpf/bpf.c | 10 ++++ tools/lib/bpf/bpf.h | 1 + tools/lib/bpf/libbpf.map | 1 + .../selftests/bpf/prog_tests/enable_stats.c | 46 +++++++++++++++ .../selftests/bpf/progs/test_enable_stats.c | 18 ++++++ 10 files changed, 191 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/enable_stats.c create mode 100644 tools/testing/selftests/bpf/progs/test_enable_stats.c -- 2.24.1
