[PROPOSAL] psutil.cpu_info() (extended CPU information)

[giampaolo]

This is a generic / exploration ticket, currently useful only for collecting information on how to get CPU info on different platforms, and which I will update from time to time. The idea is to provide a psutil.cpu_info() API returning a dict (EDIT or namedtuple?) with variable keys, depending on what's available. By observing lscpu output on Linux, the idea is to have something roughly like this:

>>> psutil.cpu_info()
{"model_name": "Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz",
 "arch": "x86_64",
 "op_modes": "32-bit, 64-bit",
 "logical_cpus": 8,
 "cores_per_socket": 4,
 "sockets": 1,
 "threads_per_core": 2,
 "cores_per_sockets": 4,
 "numa_nodes": 1,
 "vendor": "GenuineIntel",
 "l1d_cache": "32000",
 "l1i_cache": "32000",
 "l2_cache": "256000",
 "l3_cache": "6144000",
 "flags": "fpu vme de pse tsc msr pae ..."}}

Note that the information re. the number of cores/sockets, etc. intersect with another proposal I made in #1392 (comment), where I (roughly) suggest a re-adaptation of psutil's cpu_count() API. That must be taken info consideration as possibly we would end up with 2 ways of doing the same thing, but cpu_count() should be preferred as "more standard":

psutil.cpu_count(kind="logical")  
psutil.cpu_count(kind="cores")
psutil.cpu_count(kind="sockets")  
psutil.cpu_count(kind="usable")
psutil.cpu_count(kind="numa")

The number of CPU types is not strictly related with this proposal though. The point of cpu_info() is the provide more "human readable", non-strictly-standardized information.

Minimum information

According to lscpu on Linux and sysctl.h on macOS, it seems to me the bare minimum info we should provide on all platforms should be the following (but didn't check Windows yet):

• model name
• L1I cache size
• L1D cache size
• L3 cache size
• number of sockets
• byte order (little/big endian)
• flags / features

Platform notes / implementations

Linux

• lscpu.c source code
• cat /proc/cpuinfo output
• lscpu output
• lscpu -J (JSON) output, in case we'll end up parsing it (likely)

macOS

• sysctl.h interface
• sysctl -a | grep machdep.cp output:

machdep.cpu.max_basic: 22
machdep.cpu.max_ext: 2147483656
machdep.cpu.vendor: GenuineIntel
machdep.cpu.brand_string: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
machdep.cpu.family: 6
machdep.cpu.model: 30
machdep.cpu.extmodel: 1
machdep.cpu.extfamily: 0
machdep.cpu.stepping: 5
machdep.cpu.feature_bits: 9266193621400157183
machdep.cpu.extfeature_bits: 1241917688064
machdep.cpu.signature: 67301
machdep.cpu.brand: 0
machdep.cpu.features: FPU VME DE PSE TSC MSR PAE MCE CX8 APIC SEP MTRR PGE MCA CMOV PAT PSE36 CLFSH MMX FXSR SSE SSE2 HTT SSE3 SSSE3 CX16 SSE4.1 SSE4.2 POPCNT VMM
machdep.cpu.extfeatures: SYSCALL XD EM64T LAHF LZCNT PREFETCHW RDTSCP TSCI
machdep.cpu.logical_per_package: 2
machdep.cpu.cores_per_package: 2
machdep.cpu.microcode_version: 0
machdep.cpu.processor_flag: 1
machdep.cpu.mwait.linesize_min: 0
machdep.cpu.mwait.linesize_max: 0
machdep.cpu.mwait.extensions: 3
machdep.cpu.mwait.sub_Cstates: 0
machdep.cpu.thermal.sensor: 0
machdep.cpu.thermal.dynamic_acceleration: 0
machdep.cpu.thermal.invariant_APIC_timer: 0
machdep.cpu.thermal.thresholds: 0
machdep.cpu.thermal.ACNT_MCNT: 0
machdep.cpu.thermal.core_power_limits: 0
machdep.cpu.thermal.fine_grain_clock_mod: 0
machdep.cpu.thermal.package_thermal_intr: 0
machdep.cpu.thermal.hardware_feedback: 0
machdep.cpu.thermal.energy_policy: 0
machdep.cpu.xsave.extended_state: 0 0 0 0
machdep.cpu.xsave.extended_state1: 0 0 0 0
machdep.cpu.arch_perf.version: 0
machdep.cpu.arch_perf.number: 0
machdep.cpu.arch_perf.width: 0
machdep.cpu.arch_perf.events_number: 0
machdep.cpu.arch_perf.events: 0
machdep.cpu.arch_perf.fixed_number: 0
machdep.cpu.arch_perf.fixed_width: 0
machdep.cpu.cache.linesize: 64
machdep.cpu.cache.L2_associativity: 4
machdep.cpu.cache.size: 256
machdep.cpu.tlb.inst.large: 8
machdep.cpu.tlb.data.small: 64
machdep.cpu.tlb.data.small_level1: 64
machdep.cpu.address_bits.physical: 39
machdep.cpu.address_bits.virtual: 48
machdep.cpu.core_count: 2
machdep.cpu.thread_count: 2
machdep.cpu.tsc_ccc.numerator: 0
machdep.cpu.tsc_ccc.denominator: 0

Windows

TODO

FreeBSD

• https://www.cyberciti.biz/faq/howto-find-out-freebsd-cpuinfo/
• https://serverfault.com/a/554442
• cpuid command (https://github.com/X0rg/CPU-X/)
• cpu-x command
• lscpu.c porting

Other platforms

• https://github.com/kernelslacker/x86info
• cpu-x https://github.com/X0rg/CPU-X/ (FreeBSD, Linux)

Considerations / open questions

• in case there's more than 1 physical CPU on the system, the API may return a list of dicts (cpu_info(percpu=True)), but that would be a mess in terms of implementation and probably not portable, so it should not be supported.

[Sub-7]

Json output of the core load would be nice.

psutil.cpu_percent(interval=1, percpu=True)
[0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]