BPF_METADATA_KEY_LEN - Linux

Symbol: BPF_METADATA_KEY_LEN

tools/lib/perf/include/perf/event.h

char key[BPF_METADATA_KEY_LEN];

tools/perf/util/bpf-event.c

snprintf(entry->key, BPF_METADATA_KEY_LEN, "%s", name);