Future ABI changes================== This file collects items that require a libperf ABI bump.  Each entryshould describe the current limitation, the desired end state, and thescope of the change so that a future ABI revision can batch themtogether. 1. Widen struct perf_cpu.cpu from int16_t to int   - Current limit: 32767 CPUs.  No architecture exceeds this today     (x86_64 max is 8192, arm64 is 4096), but NR_CPUS limits keep     growing.  perf clamps to INT16_MAX in set_max_cpu_num() as a     safety net.   - Code simplification: the int16_t forces defensive truncation     checks at every boundary where a wider CPU index (int from     sample->cpu, al->cpu, etc.) is narrowed into struct perf_cpu.     Without these checks, values > 32767 silently wrap to negative     numbers (two's complement), bypassing bounds validation.     Widening to int eliminates this entire class of silent     truncation bugs and removes the need for the INT16_MAX clamp     in set_max_cpu_num().   - Scope: struct perf_cpu is embedded everywhere — perf_cpu_map__cpu(),     perf_cpu_map__min(), perf_cpu_map__max(), perf_cpu_map__has(), the     for_each_cpu macros, and all internal callers.  The perf_cpu_map     internal array (RC_CHK_ACCESS(map)->map[]) stores struct perf_cpu     directly.  Widening changes the struct layout and every function     that returns or accepts struct perf_cpu by value.   - Migration: bump LIBPERF version in libperf.map, audit all     sizeof(struct perf_cpu) assumptions, update perf.data     serialization if needed.