When run in Docker psutil returns threads as physical cores

[rightisleft]

Problem:
Given that i am running inside a docker container,
When i run psutil.cpu_count(logical=False),
Then it should only return the number of cores AND exclude threads

What i'm seeing
I'm running docker on OS X. When i test psutil.cpu_count(logical=False) on my macbook, i get the following:

OS X

$ python                                                                                                                                                                                                                                                               
Python 2.7.10 (default, Oct  6 2017, 22:29:07)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.31)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import psutil
>>> psutil.cpu_count(logical=False)
4

DOCKER VIA OS X

$docker run -it --rm python:2.7.15-jessie bash
root@314fa2429746:/# pip install psutil
root@314fa2429746:/# python
>>> import psutil
>>> psutil.cpu_count(logical=False)
8
>>>

Actual Hardware:
https://ark.intel.com/products/65524/Intel-Core-i7-3770S-Processor-8M-Cache-up-to-3_90-GHz

[giampaolo]

You can check what the kernel says with the following commands:

osx:psutil vagrant$ sysctl -a | grep physicalcpu
osx:psutil vagrant$ sysctl -a | grep logicalcpu

That's basically what psutil does (in C).

[rightisleft]

Odd response:

root$ sysctl -a | grep logicalcpu
sysctl: reading key "net.ipv6.conf.all.stable_secret"
sysctl: reading key "net.ipv6.conf.default.stable_secret"
sysctl: reading key "net.ipv6.conf.eth0.stable_secret"
sysctl: reading key "net.ipv6.conf.ip6tnl0.stable_secret"
sysctl: reading key "net.ipv6.conf.lo.stable_secret"

$ sysctl -a | grep physicalcpu
sysctl: reading key "net.ipv6.conf.all.stable_secret"
sysctl: reading key "net.ipv6.conf.default.stable_secret"
sysctl: reading key "net.ipv6.conf.eth0.stable_secret"
sysctl: reading key "net.ipv6.conf.ip6tnl0.stable_secret"
sysctl: reading key "net.ipv6.conf.lo.stable_secret"

Simplifying to grep cpu returns:

$ sysctl -a | grep cpu
kernel.hardlockup_all_cpu_backtrace = 0
kernel.perf_cpu_time_max_percent = 25
kernel.sched_domain.cpu0.domain0.busy_factor = 32
kernel.sched_domain.cpu0.domain0.busy_idx = 2
kernel.sched_domain.cpu0.domain0.cache_nice_tries = 1
kernel.sched_domain.cpu0.domain0.flags = 4143
kernel.sched_domain.cpu0.domain0.forkexec_idx = 0
kernel.sched_domain.cpu0.domain0.idle_idx = 1
kernel.sched_domain.cpu0.domain0.imbalance_pct = 125
kernel.sched_domain.cpu0.domain0.max_interval = 16
kernel.sched_domain.cpu0.domain0.max_newidle_lb_cost = 83084
kernel.sched_domain.cpu0.domain0.min_interval = 8
kernel.sched_domain.cpu0.domain0.name = DIE
kernel.sched_domain.cpu0.domain0.newidle_idx = 0
kernel.sched_domain.cpu0.domain0.wake_idx = 0
kernel.sched_domain.cpu1.domain0.busy_factor = 32
kernel.sched_domain.cpu1.domain0.busy_idx = 2
kernel.sched_domain.cpu1.domain0.cache_nice_tries = 1
kernel.sched_domain.cpu1.domain0.flags = 4143
kernel.sched_domain.cpu1.domain0.forkexec_idx = 0
kernel.sched_domain.cpu1.domain0.idle_idx = 1
kernel.sched_domain.cpu1.domain0.imbalance_pct = 125
kernel.sched_domain.cpu1.domain0.max_interval = 16
kernel.sched_domain.cpu1.domain0.max_newidle_lb_cost = 75211
kernel.sched_domain.cpu1.domain0.min_interval = 8
kernel.sched_domain.cpu1.domain0.name = DIE
kernel.sched_domain.cpu1.domain0.newidle_idx = 0
kernel.sched_domain.cpu1.domain0.wake_idx = 0
kernel.sched_domain.cpu2.domain0.busy_factor = 32
kernel.sched_domain.cpu2.domain0.busy_idx = 2
kernel.sched_domain.cpu2.domain0.cache_nice_tries = 1
kernel.sched_domain.cpu2.domain0.flags = 4143
kernel.sched_domain.cpu2.domain0.forkexec_idx = 0
kernel.sched_domain.cpu2.domain0.idle_idx = 1
kernel.sched_domain.cpu2.domain0.imbalance_pct = 125
kernel.sched_domain.cpu2.domain0.max_interval = 16
kernel.sched_domain.cpu2.domain0.max_newidle_lb_cost = 162222
kernel.sched_domain.cpu2.domain0.min_interval = 8
kernel.sched_domain.cpu2.domain0.name = DIE
kernel.sched_domain.cpu2.domain0.newidle_idx = 0
kernel.sched_domain.cpu2.domain0.wake_idx = 0
kernel.sched_domain.cpu3.domain0.busy_factor = 32
kernel.sched_domain.cpu3.domain0.busy_idx = 2
kernel.sched_domain.cpu3.domain0.cache_nice_tries = 1
kernel.sched_domain.cpu3.domain0.flags = 4143
kernel.sched_domain.cpu3.domain0.forkexec_idx = 0
kernel.sched_domain.cpu3.domain0.idle_idx = 1
kernel.sched_domain.cpu3.domain0.imbalance_pct = 125
kernel.sched_domain.cpu3.domain0.max_interval = 16
kernel.sched_domain.cpu3.domain0.max_newidle_lb_cost = 77418
kernel.sched_domain.cpu3.domain0.min_interval = 8
kernel.sched_domain.cpu3.domain0.name = DIE
kernel.sched_domain.cpu3.domain0.newidle_idx = 0
kernel.sched_domain.cpu3.domain0.wake_idx = 0
kernel.sched_domain.cpu4.domain0.busy_factor = 32
kernel.sched_domain.cpu4.domain0.busy_idx = 2
kernel.sched_domain.cpu4.domain0.cache_nice_tries = 1
kernel.sched_domain.cpu4.domain0.flags = 4143
kernel.sched_domain.cpu4.domain0.forkexec_idx = 0
kernel.sched_domain.cpu4.domain0.idle_idx = 1
kernel.sched_domain.cpu4.domain0.imbalance_pct = 125
kernel.sched_domain.cpu4.domain0.max_interval = 16
kernel.sched_domain.cpu4.domain0.max_newidle_lb_cost = 503799
kernel.sched_domain.cpu4.domain0.min_interval = 8
kernel.sched_domain.cpu4.domain0.name = DIE
kernel.sched_domain.cpu4.domain0.newidle_idx = 0
kernel.sched_domain.cpu4.domain0.wake_idx = 0
kernel.sched_domain.cpu5.domain0.busy_factor = 32
kernel.sched_domain.cpu5.domain0.busy_idx = 2
kernel.sched_domain.cpu5.domain0.cache_nice_tries = 1
kernel.sched_domain.cpu5.domain0.flags = 4143
kernel.sched_domain.cpu5.domain0.forkexec_idx = 0
kernel.sched_domain.cpu5.domain0.idle_idx = 1
kernel.sched_domain.cpu5.domain0.imbalance_pct = 125
kernel.sched_domain.cpu5.domain0.max_interval = 16
kernel.sched_domain.cpu5.domain0.max_newidle_lb_cost = 81770
kernel.sched_domain.cpu5.domain0.min_interval = 8
kernel.sched_domain.cpu5.domain0.name = DIE
kernel.sched_domain.cpu5.domain0.newidle_idx = 0
kernel.sched_domain.cpu5.domain0.wake_idx = 0
kernel.sched_domain.cpu6.domain0.busy_factor = 32
kernel.sched_domain.cpu6.domain0.busy_idx = 2
kernel.sched_domain.cpu6.domain0.cache_nice_tries = 1
kernel.sched_domain.cpu6.domain0.flags = 4143
kernel.sched_domain.cpu6.domain0.forkexec_idx = 0
kernel.sched_domain.cpu6.domain0.idle_idx = 1
kernel.sched_domain.cpu6.domain0.imbalance_pct = 125
kernel.sched_domain.cpu6.domain0.max_interval = 16
kernel.sched_domain.cpu6.domain0.max_newidle_lb_cost = 502189
kernel.sched_domain.cpu6.domain0.min_interval = 8
kernel.sched_domain.cpu6.domain0.name = DIE
kernel.sched_domain.cpu6.domain0.newidle_idx = 0
kernel.sched_domain.cpu6.domain0.wake_idx = 0
kernel.sched_domain.cpu7.domain0.busy_factor = 32
kernel.sched_domain.cpu7.domain0.busy_idx = 2
kernel.sched_domain.cpu7.domain0.cache_nice_tries = 1
kernel.sched_domain.cpu7.domain0.flags = 4143
kernel.sched_domain.cpu7.domain0.forkexec_idx = 0
kernel.sched_domain.cpu7.domain0.idle_idx = 1
kernel.sched_domain.cpu7.domain0.imbalance_pct = 125
kernel.sched_domain.cpu7.domain0.max_interval = 16
kernel.sched_domain.cpu7.domain0.max_newidle_lb_cost = 126056
kernel.sched_domain.cpu7.domain0.min_interval = 8
kernel.sched_domain.cpu7.domain0.name = DIE
kernel.sched_domain.cpu7.domain0.newidle_idx = 0
kernel.sched_domain.cpu7.domain0.wake_idx = 0
kernel.softlockup_all_cpu_backtrace = 0
kernel.watchdog_cpumask = 0-7
sysctl: reading key "net.ipv6.conf.all.stable_secret"
sysctl: reading key "net.ipv6.conf.default.stable_secret"
sysctl: reading key "net.ipv6.conf.eth0.stable_secret"
sysctl: reading key "net.ipv6.conf.ip6tnl0.stable_secret"
sysctl: reading key "net.ipv6.conf.lo.stable_secret"
vm.percpu_pagelist_fraction = 0

[giampaolo]

You basically don't have physicalcpu and logicalcpu values. Weird... Not sure what to suggest as psutil takes those values directly from the kernel so technically they are not debatable. :-\

[giampaolo]

Closing as it seems a problem with docker.