BSD (2 clause) License Linux/Mac build status Windows build status
cpuinfo is a library to detect essential for performance optimization information about host CPU.
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();constsize_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);conststruct 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 $libcpuinfo_LIBS"
To use with Meson you just need to add dependency('libcpuinfo') as a dependency for your executable.
project('MyCpuInfoProject','cpp', meson_version:'>=0.55.0') executable('MyCpuInfoExecutable', sources:'main.cpp', dependencies: dependency('libcpuinfo'))
This project can be built using Bazel.
You can also use this library as a dependency to your Bazel project. Add to your MODULE.bazel file:
# fetch cpuinfo from Bazel Central Registry: https://registry.bazel.build/modules/cpuinfo bazel_dep(name ="cpuinfo", version ="0.0.0-20250925-877328f")# Optional: Override it with some specific commit hash git_override( module_name ="cpuinfo", commit ="<replace_with_commit_hash>" remote ="https://github.com/pytorch/cpuinfo.git",)
And to your BUILD file:
cc_binary( name ="cpuinfo_test", srcs =[# ...], deps =["@cpuinfo",],)
To use with CMake use the FindPkgConfig module. Here is an example:
cmake_minimum_required(VERSION 3.6) project("MyCpuInfoProject") find_package(PkgConfig) pkg_check_modules(CpuInfo REQUIRED IMPORTED_TARGET libcpuinfo) add_executable(${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)
/proc/cpuinfo on ARMro.chipname, ro.board.platform, ro.product.board, ro.mediatek.platform, ro.arch properties (Android)dmesg) on ARM Linux/proc/cpuinfo on 32-bit ARM EABI (Linux)FPSID and WCID registers (32-bit ARM)getauxval (Linux/ARM)/proc/self/auxv (Android/ARM)/proc/cpuinfo (Linux/pre-ARMv7)sysctlbyname (Mach)typology directories (ARM/Linux)cache directories (Linux)GetLogicalProcessorInformationEx on ARM64 Windows/proc/cpuinfo (Linux)host_info (Mach)GetLogicalProcessorInformationEx (Windows)