From 02a79520594b77d85d9c96bf7d65a405839762d5 Mon Sep 17 00:00:00 2001 From: Markus Lehtonen Date: Tue, 15 Feb 2022 10:25:46 +0200 Subject: [PATCH] docs: document rdt related annotations --- docs/policy/rdt.md | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/docs/policy/rdt.md b/docs/policy/rdt.md index f9199b2da..48dc2cdcf 100644 --- a/docs/policy/rdt.md +++ b/docs/policy/rdt.md @@ -24,15 +24,30 @@ Classes of Service (CLOS) (under `/sys/fs/resctrl`) corresponding the RDT class. the CLOSes according to its configuration at startup or whenever the configuration changes. -By default there is a direct mapping between Pod QoS classes and RDT classes: -the containers of the Pod get an RDT class with the same name as its QoS class -(Guaranteed, Burstable or Besteffort). However, that can be overridden with the -`rdtclass.cri-resource-manager.intel.com` Pod annotation. You can also specify -RDT classes other than Guaranteed, Burstable or Besteffort. In this case, the -Pod can only be assigned to these classes with the Pod annotation, though. -The default behavior can also be overridden by a policy but currently none of -the builtin policies do that. +CRI-RM maintains a direct mapping between Pod QoS classes and RDT classes. If +RDT is enabled CRI-RM tries to assign containers into an RDT class with a name +matching their Pod QoS class. This default behavior can be overridden with +pod annotations. +## Class Assignment + +By default, containers get an RDT class with the same name as its Pod QoS class +(Guaranteed, Burstable or Besteffort). If the RDT class is missing the +container will be assigned to the system root class. + +The default behavior can be overridden with pod annoations: + +- `rdtclass.cri-resource-manager.intel.com/pod: ` specifies a + pod-level default that will be used for all containers of a pod +- `rdtclass.cri-resource-manager.intel.com/container.: ` + specifies container-specific assignment, taking preference over possible + pod-level annotation (above) + +With pod annoations it is possible to specify RDT classes other than +Guaranteed, Burstable or Besteffort. + +The default assignment could also be overridden by a policy but currently none +of the builtin policies do that. ## Configuration