From f2186adb445f1420184aa5af5536bb777536a798 Mon Sep 17 00:00:00 2001 From: Gleb Aronsky Date: Mon, 24 Jan 2022 15:52:24 -0500 Subject: [PATCH] kubelet cpumanager keep normal containers off reserved CPUs When starting the kubelet process, two separate sets of reserved CPUs may be specified. With this change CPUs reserved via '--system-reserved=cpu' or '--kube-reserved=cpu' will be ignored by kubernetes itself. A small tweak to the default CPU affinity ensures that "normal" Kubernetes pods won't run on the reserved CPUs. Co-authored-by: Jim Gauld Signed-off-by: Gleb Aronsky --- pkg/kubelet/cm/cpumanager/cpu_manager.go | 6 ++- pkg/kubelet/cm/cpumanager/cpu_manager_test.go | 11 ++++-- pkg/kubelet/cm/cpumanager/policy_static.go | 29 +++++++++++--- .../cm/cpumanager/policy_static_test.go | 38 ++++++++++++++----- 4 files changed, 64 insertions(+), 20 deletions(-) diff --git a/pkg/kubelet/cm/cpumanager/cpu_manager.go b/pkg/kubelet/cm/cpumanager/cpu_manager.go index 6ad289336ea..8336e7b0fd4 100644 --- a/pkg/kubelet/cm/cpumanager/cpu_manager.go +++ b/pkg/kubelet/cm/cpumanager/cpu_manager.go @@ -191,7 +191,11 @@ func NewManager(cpuPolicyName string, cpuPolicyOptions map[string]string, reconc // exclusively allocated. reservedCPUsFloat := float64(reservedCPUs.MilliValue()) / 1000 numReservedCPUs := int(math.Ceil(reservedCPUsFloat)) - policy, err = NewStaticPolicy(topo, numReservedCPUs, specificCPUs, affinity, cpuPolicyOptions) + // NOTE: Set excludeReserved unconditionally to exclude reserved CPUs from default cpuset. + // This variable is primarily to make testing easier. + excludeReserved := true + policy, err = NewStaticPolicy(topo, numReservedCPUs, specificCPUs, affinity, cpuPolicyOptions, excludeReserved) + if err != nil { return nil, fmt.Errorf("new static policy error: %w", err) } diff --git a/pkg/kubelet/cm/cpumanager/cpu_manager_test.go b/pkg/kubelet/cm/cpumanager/cpu_manager_test.go index 9b3e24fc3b2..2c8349662c4 100644 --- a/pkg/kubelet/cm/cpumanager/cpu_manager_test.go +++ b/pkg/kubelet/cm/cpumanager/cpu_manager_test.go @@ -215,6 +215,7 @@ func makeMultiContainerPod(initCPUs, appCPUs []struct{ request, limit string }) } func TestCPUManagerAdd(t *testing.T) { + testExcl := false testPolicy, _ := NewStaticPolicy( &topology.CPUTopology{ NumCPUs: 4, @@ -230,7 +231,8 @@ func TestCPUManagerAdd(t *testing.T) { 0, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), - nil) + nil, + testExcl) testCases := []struct { description string updateErr error @@ -479,8 +481,9 @@ func TestCPUManagerAddWithInitContainers(t *testing.T) { }, } + testExcl := false for _, testCase := range testCases { - policy, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil) + policy, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil, testExcl) mockState := &mockState{ assignments: testCase.stAssignments, @@ -1228,6 +1231,7 @@ func TestReconcileState(t *testing.T) { // above test cases are without kubelet --reserved-cpus cmd option // the following tests are with --reserved-cpus configured func TestCPUManagerAddWithResvList(t *testing.T) { + testExcl := false testPolicy, _ := NewStaticPolicy( &topology.CPUTopology{ NumCPUs: 4, @@ -1243,7 +1247,8 @@ func TestCPUManagerAddWithResvList(t *testing.T) { 1, cpuset.NewCPUSet(0), topologymanager.NewFakeManager(), - nil) + nil, + testExcl) testCases := []struct { description string updateErr error diff --git a/pkg/kubelet/cm/cpumanager/policy_static.go b/pkg/kubelet/cm/cpumanager/policy_static.go index f7ff26cd313..9697f4d4bb0 100644 --- a/pkg/kubelet/cm/cpumanager/policy_static.go +++ b/pkg/kubelet/cm/cpumanager/policy_static.go @@ -96,6 +96,8 @@ type staticPolicy struct { topology *topology.CPUTopology // set of CPUs that is not available for exclusive assignment reserved cpuset.CPUSet + // If true, default CPUSet should exclude reserved CPUs + excludeReserved bool // topology manager reference to get container Topology affinity affinity topologymanager.Store // set of CPUs to reuse across allocations in a pod @@ -110,7 +112,7 @@ var _ Policy = &staticPolicy{} // NewStaticPolicy returns a CPU manager policy that does not change CPU // assignments for exclusively pinned guaranteed containers after the main // container process starts. -func NewStaticPolicy(topology *topology.CPUTopology, numReservedCPUs int, reservedCPUs cpuset.CPUSet, affinity topologymanager.Store, cpuPolicyOptions map[string]string) (Policy, error) { +func NewStaticPolicy(topology *topology.CPUTopology, numReservedCPUs int, reservedCPUs cpuset.CPUSet, affinity topologymanager.Store, cpuPolicyOptions map[string]string, excludeReserved bool) (Policy, error) { opts, err := NewStaticPolicyOptions(cpuPolicyOptions) if err != nil { return nil, err @@ -172,7 +174,15 @@ func (p *staticPolicy) validateState(s state.State) error { } // state is empty initialize allCPUs := p.topology.CPUDetails.CPUs() - s.SetDefaultCPUSet(allCPUs) + if p.excludeReserved { + // Exclude reserved CPUs from the default CPUSet to keep containers off them + // unless explicitly affined. + s.SetDefaultCPUSet(allCPUs.Difference(p.reserved)) + } else { + s.SetDefaultCPUSet(allCPUs) + } + klog.Infof("[cpumanager] static policy: CPUSet: allCPUs:%v, reserved:%v, default:%v\n", + allCPUs, p.reserved, s.GetDefaultCPUSet()) return nil } @@ -180,11 +190,12 @@ func (p *staticPolicy) validateState(s state.State) error { // 1. Check if the reserved cpuset is not part of default cpuset because: // - kube/system reserved have changed (increased) - may lead to some containers not being able to start // - user tampered with file - if !p.reserved.Intersection(tmpDefaultCPUset).Equals(p.reserved) { - return fmt.Errorf("not all reserved cpus: \"%s\" are present in defaultCpuSet: \"%s\"", - p.reserved.String(), tmpDefaultCPUset.String()) + if !p.excludeReserved { + if !p.reserved.Intersection(tmpDefaultCPUset).Equals(p.reserved) { + return fmt.Errorf("not all reserved cpus: \"%s\" are present in defaultCpuSet: \"%s\"", + p.reserved.String(), tmpDefaultCPUset.String()) + } } - // 2. Check if state for static policy is consistent for pod := range tmpAssignments { for container, cset := range tmpAssignments[pod] { @@ -211,6 +222,9 @@ func (p *staticPolicy) validateState(s state.State) error { } } totalKnownCPUs = totalKnownCPUs.UnionAll(tmpCPUSets) + if p.excludeReserved { + totalKnownCPUs = totalKnownCPUs.Union(p.reserved) + } if !totalKnownCPUs.Equals(p.topology.CPUDetails.CPUs()) { return fmt.Errorf("current set of available CPUs \"%s\" doesn't match with CPUs in state \"%s\"", p.topology.CPUDetails.CPUs().String(), totalKnownCPUs.String()) @@ -296,6 +310,9 @@ func (p *staticPolicy) RemoveContainer(s state.State, podUID string, containerNa klog.InfoS("Static policy: RemoveContainer", "podUID", podUID, "containerName", containerName) if toRelease, ok := s.GetCPUSet(podUID, containerName); ok { s.Delete(podUID, containerName) + if p.excludeReserved { + toRelease = toRelease.Difference(p.reserved) + } // Mutate the shared pool, adding released cpus. s.SetDefaultCPUSet(s.GetDefaultCPUSet().Union(toRelease)) } diff --git a/pkg/kubelet/cm/cpumanager/policy_static_test.go b/pkg/kubelet/cm/cpumanager/policy_static_test.go index d2b641fe3a0..80bd04a1f92 100644 --- a/pkg/kubelet/cm/cpumanager/policy_static_test.go +++ b/pkg/kubelet/cm/cpumanager/policy_static_test.go @@ -33,6 +33,7 @@ type staticPolicyTest struct { description string topo *topology.CPUTopology numReservedCPUs int + excludeReserved bool podUID string options map[string]string containerName string @@ -64,7 +65,8 @@ func (spt staticPolicyTest) PseudoClone() staticPolicyTest { } func TestStaticPolicyName(t *testing.T) { - policy, _ := NewStaticPolicy(topoSingleSocketHT, 1, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil) + testExcl := false + policy, _ := NewStaticPolicy(topoSingleSocketHT, 1, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil, testExcl) policyName := policy.Name() if policyName != "static" { @@ -94,6 +96,15 @@ func TestStaticPolicyStart(t *testing.T) { stDefaultCPUSet: cpuset.NewCPUSet(), expCSet: cpuset.NewCPUSet(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11), }, + { + description: "empty cpuset exclude reserved", + topo: topoDualSocketHT, + numReservedCPUs: 2, + excludeReserved: true, + stAssignments: state.ContainerCPUAssignments{}, + stDefaultCPUSet: cpuset.NewCPUSet(), + expCSet: cpuset.NewCPUSet(1, 2, 3, 4, 5, 7, 8, 9, 10, 11), + }, { description: "reserved cores 0 & 6 are not present in available cpuset", topo: topoDualSocketHT, @@ -140,7 +151,8 @@ func TestStaticPolicyStart(t *testing.T) { } for _, testCase := range testCases { t.Run(testCase.description, func(t *testing.T) { - p, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil) + p, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil, testCase.excludeReserved) + policy := p.(*staticPolicy) st := &mockState{ assignments: testCase.stAssignments, @@ -211,7 +223,7 @@ func TestStaticPolicyAdd(t *testing.T) { "fakeContainer100": cpuset.NewCPUSet(2, 3, 6, 7), }, }, - stDefaultCPUSet: cpuset.NewCPUSet(0, 1, 4, 5), + stDefaultCPUSet: cpuset.NewCPUSet(4, 5), pod: makePod("fakePod", "fakeContainer3", "2000m", "2000m"), expErr: nil, expCPUAlloc: true, @@ -517,7 +529,8 @@ func TestStaticPolicyAdd(t *testing.T) { } func runStaticPolicyTestCase(t *testing.T, testCase staticPolicyTest) { - policy, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), testCase.options) + testExcl := false + policy, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), testCase.options, testExcl) st := &mockState{ assignments: testCase.stAssignments, @@ -559,6 +572,7 @@ func runStaticPolicyTestCase(t *testing.T, testCase staticPolicyTest) { } func TestStaticPolicyRemove(t *testing.T) { + excludeReserved := false testCases := []staticPolicyTest{ { description: "SingleSocketHT, DeAllocOneContainer", @@ -617,7 +631,7 @@ func TestStaticPolicyRemove(t *testing.T) { } for _, testCase := range testCases { - policy, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil) + policy, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil, testCase.excludeReserved) st := &mockState{ assignments: testCase.stAssignments, @@ -639,6 +653,7 @@ func TestStaticPolicyRemove(t *testing.T) { } func TestTopologyAwareAllocateCPUs(t *testing.T) { + excludeReserved := false testCases := []struct { description string topo *topology.CPUTopology @@ -707,7 +722,7 @@ func TestTopologyAwareAllocateCPUs(t *testing.T) { }, } for _, tc := range testCases { - p, _ := NewStaticPolicy(tc.topo, 0, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil) + p, _ := NewStaticPolicy(tc.topo, 0, cpuset.NewCPUSet(), topologymanager.NewFakeManager(), nil, excludeReserved) policy := p.(*staticPolicy) st := &mockState{ assignments: tc.stAssignments, @@ -779,9 +794,11 @@ func TestStaticPolicyStartWithResvList(t *testing.T) { expNewErr: fmt.Errorf("[cpumanager] unable to reserve the required amount of CPUs (size of 0-1 did not equal 1)"), }, } + testExcl := false for _, testCase := range testCases { t.Run(testCase.description, func(t *testing.T) { - p, err := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, testCase.reserved, topologymanager.NewFakeManager(), nil) + p, err := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, testCase.reserved, topologymanager.NewFakeManager(), nil, testExcl) + if !reflect.DeepEqual(err, testCase.expNewErr) { t.Errorf("StaticPolicy Start() error (%v). expected error: %v but got: %v", testCase.description, testCase.expNewErr, err) @@ -821,7 +838,7 @@ func TestStaticPolicyAddWithResvList(t *testing.T) { numReservedCPUs: 1, reserved: cpuset.NewCPUSet(0), stAssignments: state.ContainerCPUAssignments{}, - stDefaultCPUSet: cpuset.NewCPUSet(0, 1, 2, 3, 4, 5, 6, 7), + stDefaultCPUSet: cpuset.NewCPUSet(1, 2, 3, 4, 5, 6, 7), pod: makePod("fakePod", "fakeContainer2", "8000m", "8000m"), expErr: fmt.Errorf("not enough cpus available to satisfy request"), expCPUAlloc: false, @@ -833,7 +850,7 @@ func TestStaticPolicyAddWithResvList(t *testing.T) { numReservedCPUs: 2, reserved: cpuset.NewCPUSet(0, 1), stAssignments: state.ContainerCPUAssignments{}, - stDefaultCPUSet: cpuset.NewCPUSet(0, 1, 2, 3, 4, 5, 6, 7), + stDefaultCPUSet: cpuset.NewCPUSet(2, 3, 4, 5, 6, 7), pod: makePod("fakePod", "fakeContainer2", "1000m", "1000m"), expErr: nil, expCPUAlloc: true, @@ -857,8 +874,9 @@ func TestStaticPolicyAddWithResvList(t *testing.T) { }, } + testExcl := true for _, testCase := range testCases { - policy, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, testCase.reserved, topologymanager.NewFakeManager(), nil) + policy, _ := NewStaticPolicy(testCase.topo, testCase.numReservedCPUs, testCase.reserved, topologymanager.NewFakeManager(), nil, testExcl) st := &mockState{ assignments: testCase.stAssignments, -- 2.25.1