balloons: implement CPU and memory pinning preservation

Signed-off-by: Antti Kervinen <[email protected]>
containers · Feb 14, 2024 · 68c19f8 · 68c19f8
1 parent 42457cf
commit 68c19f8
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Showing 3 changed files with 38 additions and 2 deletions.
diff --git a/cmd/plugins/balloons/policy/balloons-policy.go b/cmd/plugins/balloons/policy/balloons-policy.go
@@ -206,6 +206,10 @@ func (p *balloons) Sync(add []cache.Container, del []cache.Container) error {
 
 // AllocateResources is a resource allocation request for this policy.
 func (p *balloons) AllocateResources(c cache.Container) error {
+	if c.PreserveCpuResources() {
+		log.Infof("not handling resources of container %s, preserving CPUs %q and memory %q", c.PrettyName(), c.GetCpusetCpus(), c.GetCpusetMems())
+		return nil
+	}
 	log.Debug("allocating resources for container %s (request %d mCPU, limit %d mCPU)...",
 		c.PrettyName(),
 		p.containerRequestedMilliCpus(c.GetID()),
@@ -1367,8 +1371,12 @@ func (p *balloons) pinCpuMem(c cache.Container, cpus cpuset.CPUSet, mems idset.I
 		}
 	}
 	if p.bpoptions.PinMemory == nil || *p.bpoptions.PinMemory {
-		log.Debug("  - pinning %s to memory %s", c.PrettyName(), mems)
-		c.SetCpusetMems(mems.String())
+		if c.PreserveMemoryResources() {
+			log.Debug("  - preserving %s pinning to memory %q", c.PrettyName, c.GetCpusetMems())
+		} else {
+			log.Debug("  - pinning %s to memory %s", c.PrettyName(), mems)
+			c.SetCpusetMems(mems.String())
+		}
 	}
 }
 

diff --git a/docs/resource-policy/policy/balloons.md b/docs/resource-policy/policy/balloons.md
@@ -274,6 +274,22 @@ defined explicitly among other balloon types. If not defined, a
 built-in `default` balloon type is implicitly appended at the end of
 the balloon types list.
 
+## Disabling CPU or Memory Pinning of a Container
+
+Some containers may need to run on all CPUs or access all memories
+without restrictions. Annotate these pods and containers to prevent
+the resource policy from touching their CPU or memory pinning.
+
+```yaml
+cpu.preserve.resource-policy.nri.io/container.CONTAINER_NAME: "true"
+cpu.preserve.resource-policy.nri.io/pod: "true"
+cpu.preserve.resource-policy.nri.io: "true"
+
+memory.preserve.resource-policy.nri.io/container.CONTAINER_NAME: "true"
+memory.preserve.resource-policy.nri.io/pod: "true"
+memory.preserve.resource-policy.nri.io: "true"
+```
+
 ## Metrics and Debugging
 
 In order to enable more verbose logging and metrics exporting from the

diff --git a/test/e2e/policies.test-suite/balloons/n4c16/test05-namespace/code.var.sh b/test/e2e/policies.test-suite/balloons/n4c16/test05-namespace/code.var.sh
@@ -84,5 +84,17 @@ namespace="e2e-d" CONTCOUNT=2 create balloons-busybox
 report allowed
 verify 'cpus["pod6c0"] == cpus["pod6c1"]'
 
+
+# pod7: preserve annotation should skip placing a container into any
+# balloon even if namespace wildcard in a balloon type matches.
+CPUREQ="100m" MEMREQ="100M" CPULIM="100m" MEMLIM="100M"
+POD_ANNOTATION='cpu.preserve.resource-policy.nri.io/container.pod7c1: "true"
+    memory.preserve.resource-policy.nri.io: "true"'
+namespace="e2e-d" CONTCOUNT=3 create balloons-busybox
+report allowed
+verify 'cpus["pod6c0"] == cpus["pod7c0"]' \
+       'len(cpus["pod7c1"]) > len(cpus["pod7c0"])' \
+       'len(cpus["pod7c1"]) == 16'
+
 cleanup
 helm-terminate