* client/fingerprint: correctly fingerprint E/P cores of Apple Silicon chips
This PR adds detection of asymetric core types (Power & Efficiency) (P/E)
when running on M1/M2 Apple Silicon CPUs. This functionality is provided
by shoenig/go-m1cpu which makes use of the Apple IOKit framework to read
undocumented registers containing CPU performance data. Currently working
on getting that functionality merged upstream into gopsutil, but gopsutil
would still not support detecting P vs E cores like this PR does.
Also refactors the CPUFingerprinter code to handle the mixed core
types, now setting power vs efficiency cpu attributes.
For now the scheduler is still unaware of mixed core types - on Apple
platforms tasks cannot reserve cores anyway so it doesn't matter, but
at least now the total CPU shares available will be correct.
Future work should include adding support for detecting P/E cores on
the latest and upcoming Intel chips, where computation of total cpu shares
is currently incorrect. For that, we should also include updating the
scheduler to be core-type aware, so that tasks of resources.cores on Linux
platforms can be assigned the correct number of CPU shares for the core
type(s) they have been assigned.
node attributes before
cpu.arch = arm64
cpu.modelname = Apple M2 Pro
cpu.numcores = 12
cpu.reservablecores = 0
cpu.totalcompute = 1000
node attributes after
cpu.arch = arm64
cpu.frequency.efficiency = 2424
cpu.frequency.power = 3504
cpu.modelname = Apple M2 Pro
cpu.numcores.efficiency = 4
cpu.numcores.power = 8
cpu.reservablecores = 0
cpu.totalcompute = 37728
* fingerprint/cpu: follow up cr items
* fingerprint: add node attr for reserverable cores
Add an attribute for the number of reservable CPU cores as they may
differ from the existing `cpu.numcores` due to client configuration or
OS support.
Hopefully clarifies some confusion in #14676
* add changelog
* num_reservable_cores -> reservablecores
on Linux systems this is derived from the configure cpuset cgroup parent (defaults to /nomad)
for non Linux systems and Linux systems where cgroups are not enabled, the client defaults to using all cores
Previously, Nomad would fail to startup if the CPU fingerprinter could
not detect the cpu total compute (i.e. cores * mhz). This is common on
some EC2 instance types (graviton class), where the env_aws fingerprinter
will override the detected CPU performance with a more accurate value
anyway.
Instead of crashing on startup, have Nomad use a low default for available
cpu performance of 1000 ticks (e.g. 1 core * 1 GHz). This enables Nomad
to get past the useless cpu fingerprinting on those EC2 instances. The
crashing error message is now a log statement suggesting the setting of
cpu_total_compute in client config.
Fixes#7989
This removes a cyclical dependency when importing client/structs from
dependencies of the plugin_loader, specifically, drivers. Due to
client/config also depending on the plugin_loader.
It also better reflects the ownership of fingerprint structs, as they
are fairly internal to the fingerprint manager.
This PR:
* Uses Go 1.8 executable lookup
* Stores any err message from stats init method
* Allows overriding of Cpu Compute for hosts where it can't be detected
hc-github-team-nomad-core