cpuinfo is a library to detect essential for performance optimization information about host CPU.
- 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)
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 supports 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);
If you would like to provide your project's build environment with the necessary compiler and linker flags in a portable manner, the library by default when built enables CPUINFO_BUILD_PKG_CONFIG
and will generate a pkg-config manifest (libcpuinfo.pc). Here are several examples of how to use it:
If you used your distro's package manager to install the library, you can verify that it is available to your build environment like so:
$ pkg-config --cflags --libs libcpuinfo
-I/usr/include/x86_64-linux-gnu/ -L/lib/x86_64-linux-gnu/ -lcpuinfo
If you have installed the library from source into a non-standard prefix, pkg-config may need help finding it:
$ PKG_CONFIG_PATH="/home/me/projects/cpuinfo/prefix/lib/pkgconfig/:$PKG_CONFIG_PATH" pkg-config --cflags --libs libcpuinfo
-I/home/me/projects/cpuinfo/prefix/include -L/home/me/projects/cpuinfo/prefix/lib -lcpuinfo
To use with the GNU Autotools include the following snippet in your project's configure.ac
:
# CPU INFOrmation library...
PKG_CHECK_MODULES(
[libcpuinfo], [libcpuinfo], [],
[AC_MSG_ERROR([libcpuinfo missing...])])
YOURPROJECT_CXXFLAGS="$YOURPROJECT_CXXFLAGS $libcpuinfo_CFLAGS"
YOURPROJECT_LIBS="$YOURPROJECT_LIBS $libcpuinfo_LIBS"
To use with Meson you just need to add dependency('libcpuinfo')
as a dependency for your executable.
project(
'MyCpuInfoProject',
'cpp',
meson_version: '>=0.55.0'
)
executable(
'MyCpuInfoExecutable',
sources: 'main.cpp',
dependencies: dependency('libcpuinfo')
)
This project can be built using Bazel.
You can also use this library as a dependency to your Bazel project. Add to the WORKSPACE
file:
load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
git_repository(
name = "org_pytorch_cpuinfo",
branch = "master",
remote = "https://github.com/Vertexwahn/cpuinfo.git",
)
And to your BUILD
file:
cc_binary(
name = "cpuinfo_test",
srcs = [
# ...
],
deps = [
"@org_pytorch_cpuinfo//:cpuinfo",
],
)
To use with CMake use the FindPkgConfig module. Here is an example:
cmake_minimum_required(VERSION 3.6)
project("MyCpuInfoProject")
find_package(PkgConfig)
pkg_check_modules(CpuInfo REQUIRED IMPORTED_TARGET libcpuinfo)
add_executable(${PROJECT_NAME} main.cpp)
target_link_libraries(${PROJECT_NAME} PkgConfig::CpuInfo)
To use within a vanilla makefile, you can call pkg-config directly to supply compiler and linker flags using shell substitution.
CFLAGS=-g3 -Wall -Wextra -Werror ...
LDFLAGS=-lfoo ...
...
CFLAGS+= $(pkg-config --cflags libcpuinfo)
LDFLAGS+= $(pkg-config --libs libcpuinfo)
- Processor (SoC) name
- Microarchitecture
- Usable instruction sets
- CPU frequency
- Cache
- Size
- Associativity
- Line size
- Number of partitions
- Flags (unified, inclusive, complex hash function)
- Topology (logical processors that share this cache level)
- TLB
- Number of entries
- Associativity
- Covered page types (instruction, data)
- Covered page sizes
- Topology information
- Logical processors
- Cores
- Packages (sockets)
- Android
- x86 ABI
- x86_64 ABI
- armeabi ABI
- armeabiv7-a ABI
- arm64-v8a ABI
-
mips ABI -
mips64 ABI
- Linux
- x86
- x86-64
- 32-bit ARM (ARMv5T and later)
- ARM64
- PowerPC64
- iOS
- x86 (iPhone simulator)
- x86-64 (iPhone simulator)
- ARMv7
- ARM64
- macOS
- x86
- x86-64
- ARM64 (Apple silicon)
- Windows
- x86
- x86-64
- arm64
- Processor (SoC) name detection
- Using CPUID leaves 0x80000002–0x80000004 on x86/x86-64
- Using
/proc/cpuinfo
on ARM - Using
ro.chipname
,ro.board.platform
,ro.product.board
,ro.mediatek.platform
,ro.arch
properties (Android) - Using kernel log (
dmesg
) on ARM Linux - Using Windows registry on ARM64 Windows
- Vendor and microarchitecture detection
- Intel-designed x86/x86-64 cores (up to Sunny Cove, Goldmont Plus, and Knights Mill)
- 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)
- ARM-designed ARM cores (up to Cortex-A55, Cortex-A77, and Neoverse E1/V1/N2/V2)
- Qualcomm-designed ARM cores (Scorpion, Krait, and Kryo)
- Nvidia-designed ARM cores (Denver and Carmel)
- Samsung-designed ARM cores (Exynos)
- Intel-designed ARM cores (XScale up to 3rd-gen)
- Apple-designed ARM cores (up to Lightning and Thunder)
- Cavium-designed ARM cores (ThunderX)
- AppliedMicro-designed ARM cores (X-Gene)
- Instruction set detection
- Using CPUID (x86/x86-64)
- Using
/proc/cpuinfo
on 32-bit ARM EABI (Linux) - Using microarchitecture heuristics on (32-bit ARM)
- Using
FPSID
andWCID
registers (32-bit ARM) - Using
getauxval
(Linux/ARM) - Using
/proc/self/auxv
(Android/ARM) - Using instruction probing on ARM (Linux)
- Using CPUID registers on ARM64 (Linux)
- Using IsProcessorFeaturePresent on ARM64 Windows
- Cache detection
- Using CPUID leaf 0x00000002 (x86/x86-64)
- Using CPUID leaf 0x00000004 (non-AMD x86/x86-64)
- Using CPUID leaves 0x80000005-0x80000006 (AMD x86/x86-64)
- Using CPUID leaf 0x8000001D (AMD x86/x86-64)
- Using
/proc/cpuinfo
(Linux/pre-ARMv7) - Using microarchitecture heuristics (ARM)
- Using chipset name (ARM)
- Using
sysctlbyname
(Mach) - Using sysfs
typology
directories (ARM/Linux) - Using sysfs
cache
directories (Linux) - Using
GetLogicalProcessorInformationEx
on ARM64 Windows
- TLB detection
- Using CPUID leaf 0x00000002 (x86/x86-64)
- Using CPUID leaves 0x80000005-0x80000006 and 0x80000019 (AMD x86/x86-64)
- Using microarchitecture heuristics (ARM)
- Topology detection
- Using CPUID leaf 0x00000001 on x86/x86-64 (legacy APIC ID)
- Using CPUID leaf 0x0000000B on x86/x86-64 (Intel APIC ID)
- Using CPUID leaf 0x8000001E on x86/x86-64 (AMD APIC ID)
- Using
/proc/cpuinfo
(Linux) - Using
host_info
(Mach) - Using
GetLogicalProcessorInformationEx
(Windows) - Using sysfs (Linux)
- Using chipset name (ARM/Linux)