CPU INFOrmation library
cpuinfo is a library to detect essential for performance optimization information about host CPU.
Features
- Cross-platform availability:
- Linux, Windows, macOS, Android, and iOS operating systems
- x86, x86-64, ARM, and ARM64 architectures
- Modern C/C++ interface
- Thread-safe
- No memory allocation after initialization
- No exceptions thrown
- Detection of supported instruction sets, up to AVX512 (x86) and ARMv8.3 extensions
- Detection of SoC and core information:
- Processor (SoC) name
- Vendor and microarchitecture for each CPU core
- ID (MIDR on ARM, CPUID leaf 1 EAX value on x86) for each CPU core
- Detection of cache information:
- Cache type (instruction/data/unified), size and line size
- Cache associativity
- Cores and logical processors (hyper-threads) sharing the cache
- Detection of topology information (relative between logical processors, cores, and processor packages)
- Well-tested production-quality code:
- 60+ mock tests based on data from real devices
- Includes work-arounds for common bugs in hardware and OS kernels
- Supports systems with heterogenous cores, such as big.LITTLE and Max.Med.Min
- Permissive open-source license (Simplified BSD)
Examples
Log processor name:
cpuinfo_initialize();
printf("Running on %s CPU\n", cpuinfo_get_package(0)->name);
Detect if target is a 32-bit or 64-bit ARM system:
#if CPUINFO_ARCH_ARM || CPUINFO_ARCH_ARM64
/* 32-bit ARM-specific code here */
#endif
Check if the host CPU support ARM NEON
cpuinfo_initialize();
if (cpuinfo_has_arm_neon()) {
neon_implementation(arguments);
}
Check if the host CPU supports x86 AVX
cpuinfo_initialize();
if (cpuinfo_has_x86_avx()) {
avx_implementation(arguments);
}
Check if the thread runs on a Cortex-A53 core
cpuinfo_initialize();
switch (cpuinfo_get_current_core()->uarch) {
case cpuinfo_uarch_cortex_a53:
cortex_a53_implementation(arguments);
break;
default:
generic_implementation(arguments);
break;
}
Get the size of level 1 data cache on the fastest core in the processor (e.g. big core in big.LITTLE ARM systems):
cpuinfo_initialize();
const size_t l1_size = cpuinfo_get_processor(0)->cache.l1d->size;
Pin thread to cores sharing L2 cache with the current core (Linux or Android)
cpuinfo_initialize();
cpu_set_t cpu_set;
CPU_ZERO(&cpu_set);
const struct cpuinfo_cache* current_l2 = cpuinfo_get_current_processor()->cache.l2;
for (uint32_t i = 0; i < current_l2->processor_count; i++) {
CPU_SET(cpuinfo_get_processor(current_l2->processor_start + i)->linux_id, &cpu_set);
}
pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpu_set);
Exposed information
- [x] Processor (SoC) name
- [x] Microarchitecture
- [x] Usable instruction sets
- [ ] CPU frequency
- [x] Cache
- [x] Size
- [x] Associativity
- [x] Line size
- [x] Number of partitions
- [x] Flags (unified, inclusive, complex hash function)
- [x] Topology (logical processors that share this cache level)
- [ ] TLB
- [ ] Number of entries
- [ ] Associativity
- [ ] Covered page types (instruction, data)
- [ ] Covered page sizes
- [x] Topology information
- [x] Logical processors
- [x] Cores
- [x] Packages (sockets)
Supported environments:
- [x] Android
- [x] x86 ABI
- [x] x86_64 ABI
- [x] armeabi ABI
- [x] armeabiv7-a ABI
- [x] arm64-v8a ABI
- [ ]
mips ABI - [ ]
mips64 ABI
- [x] Linux
- [x] x86
- [x] x86-64
- [x] 32-bit ARM (ARMv5T and later)
- [x] ARM64
- [ ] PowerPC64
- [x] iOS
- [x] x86 (iPhone simulator)
- [x] x86-64 (iPhone simulator)
- [x] ARMv7
- [x] ARM64
- [x] OS X
- [x] Windows
Methods
- Processor (SoC) name detection
- [x] Using CPUID leaves 0x80000002–0x80000004 on x86/x86-64
- [x] Using
/proc/cpuinfo
on ARM - [x] Using
ro.chipname
, ro.board.platform
, ro.product.board
, ro.mediatek.platform
, ro.arch
properties (Android) - [ ] Using kernel log (
dmesg
) on ARM Linux
- Vendor and microarchitecture detection
- [x] Intel-designed x86/x86-64 cores (up to Sunny Cove, Goldmont Plus, and Knights Mill)
- [x] AMD-designed x86/x86-64 cores (up to Puma/Jaguar and Zen 2)
- [ ] VIA-designed x86/x86-64 cores
- [ ] Other x86 cores (DM&P, RDC, Transmeta, Cyrix, Rise)
- [x] ARM-designed ARM cores (up to Cortex-A55, Cortex-A77, and Neoverse E1/N1)
- [x] Qualcomm-designed ARM cores (Scorpion, Krait, and Kryo)
- [x] Nvidia-designed ARM cores (Denver and Carmel)
- [x] Samsung-designed ARM cores (Exynos)
- [x] Intel-designed ARM cores (XScale up to 3rd-gen)
- [x] Apple-designed ARM cores (up to Lightning and Thunder)
- [x] Cavium-designed ARM cores (ThunderX)
- [x] AppliedMicro-designed ARM cores (X-Gene)
- Instruction set detection
- [x] Using CPUID (x86/x86-64)
- [x] Using
/proc/cpuinfo
on 32-bit ARM EABI (Linux) - [x] Using microarchitecture heuristics on (32-bit ARM)
- [x] Using
FPSID
and WCID
registers (32-bit ARM) - [x] Using
getauxval
(Linux/ARM) - [x] Using
/proc/self/auxv
(Android/ARM) - [ ] Using instruction probing on ARM (Linux)
- [ ] Using CPUID registers on ARM64 (Linux)
- Cache detection
- [x] Using CPUID leaf 0x00000002 (x86/x86-64)
- [x] Using CPUID leaf 0x00000004 (non-AMD x86/x86-64)
- [ ] Using CPUID leaves 0x80000005-0x80000006 (AMD x86/x86-64)
- [x] Using CPUID leaf 0x8000001D (AMD x86/x86-64)
- [x] Using
/proc/cpuinfo
(Linux/pre-ARMv7) - [x] Using microarchitecture heuristics (ARM)
- [x] Using chipset name (ARM)
- [x] Using
sysctlbyname
(Mach) - [x] Using sysfs
typology
directories (ARM/Linux) - [ ] Using sysfs
cache
directories (Linux)
- TLB detection
- [x] Using CPUID leaf 0x00000002 (x86/x86-64)
- [ ] Using CPUID leaves 0x80000005-0x80000006 and 0x80000019 (AMD x86/x86-64)
- [x] Using microarchitecture heuristics (ARM)
- Topology detection
- [x] Using CPUID leaf 0x00000001 on x86/x86-64 (legacy APIC ID)
- [x] Using CPUID leaf 0x0000000B on x86/x86-64 (Intel APIC ID)
- [ ] Using CPUID leaf 0x8000001E on x86/x86-64 (AMD APIC ID)
- [x] Using
/proc/cpuinfo
(Linux) - [x] Using
host_info
(Mach) - [x] Using
GetLogicalProcessorInformationEx
(Windows) - [x] Using sysfs (Linux)
- [x] Using chipset name (ARM/Linux)