Bug: 149212952

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  1. 306cdba Change OWNERS. am: 1a30c59c53 by Xusong Wang · 4 weeks ago master
  2. 1a30c59 Change OWNERS. by Xusong Wang · 4 weeks ago
  3. 6187d8f Merge sc-mainline-prod by Xin Li · 1 year, 3 months ago android13-dev
  4. d476dee [automerger skipped] Mark ab/7061308 as merged in stage. am: 6ca2549f6b -s ours am: dc6e6c148b -s ours am: 7c83167327 -s ours by Xin Li · 1 year, 6 months ago android12-mainline-art-release android12-mainline-networkstack-release android12-mainline-tzdata3-release android-mainline-12.0.0_r100 android-mainline-12.0.0_r113 android-mainline-12.0.0_r115 android-mainline-12.0.0_r122 android-mainline-12.0.0_r19 android-mainline-12.0.0_r22 android-mainline-12.0.0_r39 android-mainline-12.0.0_r42 android-mainline-12.0.0_r49 android-mainline-12.0.0_r5 android-mainline-12.0.0_r56 android-mainline-12.0.0_r59 android-mainline-12.0.0_r63 android-mainline-12.0.0_r69 android-mainline-12.0.0_r70 android-mainline-12.0.0_r77 android-mainline-12.0.0_r98 android-mainline-12.0.0_r99
  5. ca4430c [automerger skipped] Mark ab/7061308 as merged in stage. am: 6ca2549f6b -s ours am: dc6e6c148b -s ours am: 7c83167327 -s ours by Xin Li · 1 year, 6 months ago

CPU INFOrmation library

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.


  • 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:

printf("Running on %s CPU\n", cpuinfo_get_package(0)->name);

Detect if target is a 32-bit or 64-bit ARM system:

    /* 32-bit ARM-specific code here */

Check if the host CPU support ARM NEON

if (cpuinfo_has_arm_neon()) {

Check if the host CPU supports x86 AVX

if (cpuinfo_has_x86_avx()) {

Check if the thread runs on a Cortex-A53 core

switch (cpuinfo_get_current_core()->uarch) {
    case cpuinfo_uarch_cortex_a53:

Get the size of level 1 data cache on the fastest core in the processor (e.g. big core in big.LITTLE ARM systems):

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)

cpu_set_t 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] x86
    • [x] x86-64
  • [x] Windows
    • [x] x86
    • [x] x86-64


  • 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)