PERF_REG_X86_MAX 20 arch/x86/kernel/perf_regs.c static unsigned int pt_regs_offset[PERF_REG_X86_MAX] = { PERF_REG_X86_MAX 78 arch/x86/kernel/perf_regs.c ~((1ULL << PERF_REG_X86_MAX) - 1))