2 Commits

Author	SHA1	Message	Date
Puranjay Mohan	abac8acb63	selftests/bpf: Filter timing outliers with IQR in batch-timing library ... System noise (timer interrupts, scheduling) can inflate the reported stddev. tcp-v4-syn showed stddev 37.86 ns without filtering vs 0.16 ns with filtering on the same run data. Filter samples outside [Q1 - 1.5*IQR, Q3 + 1.5*IQR] before computing statistics. Scenarios with genuinely wide distributions have large IQR so the fences stay wide and the filter has minimal effect. Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Link: https://lore.kernel.org/r/20260520133338.3392667-4-puranjay@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>	2026-05-20 09:25:47 -07:00
Puranjay Mohan	08158c111d	selftests/bpf: Add BPF batch-timing library ... Add a reusable timing library for BPF benchmarks that need to measure BPF program execution time. The BPF side (progs/bench_bpf_timing.bpf.h) provides per-CPU sample arrays and BENCH_BPF_LOOP(), a macro that brackets batch_iters iterations with bpf_ktime_get_ns() reads and records the elapsed time. One extra untimed iteration runs afterward for output validation. The userspace side (benchs/bench_bpf_timing.c) collects samples from the skeleton BSS, computes percentile statistics, and auto-calibrates batch_iters to target ~10 ms per batch. Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Link: https://lore.kernel.org/r/20260427232313.1582588-3-puranjay@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>	2026-05-11 15:25:24 -07:00