ctrreschk

ctrreschk - tooling to inspect resources assigned to containers/processes

this is an abridged version of the original README.

usage

ctrreschk is meant to be used as container entry point and performs alignment check.

In general a resource is deemed "aligned" if all its items are taken from the same pool. So, if more than a single resource pool is needed, then by definition it cannot be aligned. Example of resource pools:

• virtual cpus (Hyperthreading, SMT) are taken from physical CPUs. Usually the pool size is 2.
• CPUs (virtual or physical) are taken from a Uncore cache pool, because multiple cpus use the same uncore cache block. Usually the pool size is in the range 8-16.
• CPUs (virtual or physical) are taken from a NUMA node, because multiple cpus are physically part of a NUMA node. Usually the pool size is in the range 8-256.

online help

$ ./_out/ctrreschk 
Usage:
  ctrreschk [flags]
  ctrreschk [command]

Available Commands:
  align       show resource alignment properties
  completion  Generate the autocompletion script for the specified shell
  help        Help about any command
  info        show machine properties
  k8s         show properties in kubernetes format

Flags:
  -h, --help           help for ctrreschk
  -S, --sleepforever   run and sleep forever after executing the command
  -v, --verbose int    log verbosity

Use "ctrreschk [command] --help" for more information about a command.

here align is the most important subcommand which performs the alignment checks

$ ./_out/ctrreschk align -h
show resource alignment properties

Usage:
  ctrreschk align [flags]

Flags:
  -h, --help                 help for align
  -M, --machinedata string   read fake machine data from path, don't read real data from the system

Global Flags:
  -S, --sleepforever   run and sleep forever after executing the command
  -v, --verbose int    log verbosity

example output on developer's laptop

$ ./_out/ctrreschk align | jq .
{
  "alignment": {         <- terse summary
    "smt": true,         <- all CPUs the container is using are SMT aligned
    "llc": true,         <- ditto for LLC (uncore)
    "numa": true         <- ditto for NUMA
  },
  "aligned": {          <- breakdown of aligned resources
    "llc": {            <- LLC cpus
      "0": {            <- CPUs pertaining to LLC/Uncore block "0"
        "cpus": [
          0,
          1,
          2,
          3,
          4,
          5,
          6,
          7
        ]
      }
    },
    "numa": {           <- NUMA cpus
      "0": {            <- CPUs pertaining to NUMA node "0"
        "cpus": [
          0,
          1,
          2,
          3,
          4,
          5,
          6,
          7
        ]
      }
    }
  }
}