Port kubelet make isolcpus allocation SMT awareness to 1.22.5

Simple port of two existing patches without modification to
kubernetes 1.22.5. This enables the feature to make kubelet
isolcpus allocation SMT aware.

Story: 2008760
Task: 44190

Signed-off-by: Jim Gauld <james.gauld@windriver.com>
Change-Id: I6fb17f62d90bd6aa26b88dc7057ed7f667cf81b7
This commit is contained in:
Jim Gauld 2022-03-07 15:03:24 -05:00
parent acdd869a58
commit 2874abbeaa
3 changed files with 205 additions and 1 deletions

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@ -0,0 +1,50 @@
From ba9ab333c8b7dca5252e604837914293dc232732 Mon Sep 17 00:00:00 2001
From: Jim Gauld <James.Gauld@windriver.com>
Date: Fri, 11 Feb 2022 11:06:35 -0500
Subject: [PATCH] kubelet: sort isolcpus allocation when SMT enabled
The existing device manager code returns CPUs as devices in unsorted
order. This numerically sorts isolcpus allocations when SMT/HT is
enabled on the host. This logs SMT pairs, singletons, and algorithm
order details to make the algorithm understandable.
Signed-off-by: Jim Gauld <James.Gauld@windriver.com>
---
pkg/kubelet/cm/devicemanager/manager.go | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/pkg/kubelet/cm/devicemanager/manager.go b/pkg/kubelet/cm/devicemanager/manager.go
index 609da8ed86b..a4b247714f7 100644
--- a/pkg/kubelet/cm/devicemanager/manager.go
+++ b/pkg/kubelet/cm/devicemanager/manager.go
@@ -686,7 +686,16 @@ func order_devices_by_sibling(devices sets.String, needed int) ([]string, error)
return cpu_lst[0]
}
}
+ //Make post-analysis of selection algorithm obvious by numerical sorting
+ //the available isolated cpu_id.
+ cpu_ids := make([]int, 0, int(devices.Len()))
for cpu_id := range devices {
+ cpu_id_, _ := strconv.Atoi(cpu_id)
+ cpu_ids = append(cpu_ids, cpu_id_)
+ }
+ sort.Ints(cpu_ids)
+ for _, _cpu_id := range cpu_ids {
+ cpu_id := strconv.Itoa(_cpu_id)
// If we've already found cpu_id as a sibling, skip it.
if _, ok := _iterated_cpu[cpu_id]; ok {
continue
@@ -728,7 +737,9 @@ func order_devices_by_sibling(devices sets.String, needed int) ([]string, error)
}
}
}
- //klog.Infof("needed=%d ordered_cpu_list=%v", needed, dev_lst)
+ //This algorithm will get some attention. Show minimal details.
+ klog.Infof("order_devices_by_sibling: needed=%d, smtpairs=%v, singletons=%v, order=%v",
+ needed, sibling_lst, single_lst, dev_lst)
return dev_lst, nil
}
func smt_enabled() bool {
--
2.25.1

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@ -0,0 +1,151 @@
From 95b7b6e1ddb25511c67a3d4018f62df1e76ee7bc Mon Sep 17 00:00:00 2001
From: Tao Wang <tao.wang@windriver.com>
Date: Tue, 25 Jan 2022 19:25:45 -0500
Subject: [PATCH] kubernetes: make isolcpus allocation SMT-aware
Enhance isolcpus support in Kubernetes to allocate isolated SMT
siblings to the same container when SMT/HT is enabled on the host.
As it stands, the device manager code in Kubernetes is not SMT-aware
(since normally it doesn't deal with CPUs). However, StarlingX
exposes isolated CPUs as devices and if possible we want to allocate
all SMT siblings from a CPU core to the same container in order to
minimize cross- container interference due to resource contention
within the CPU core.
The solution is basically to take the list of isolated CPUs and
re-order it so that the SMT siblings are next to each other. That
way the existing resource selection code will allocate the siblings
together. As an optimization, if it is known that an odd number
of isolated CPUs are desired, a singleton SMT sibling will be
inserted into the list to avoid breaking up sibling pairs.
Signed-off-by: Tao Wang <tao.wang@windriver.com>
---
pkg/kubelet/cm/devicemanager/manager.go | 84 ++++++++++++++++++++++++-
1 file changed, 83 insertions(+), 1 deletion(-)
diff --git a/pkg/kubelet/cm/devicemanager/manager.go b/pkg/kubelet/cm/devicemanager/manager.go
index 60de14a9..609da8ed 100644
--- a/pkg/kubelet/cm/devicemanager/manager.go
+++ b/pkg/kubelet/cm/devicemanager/manager.go
@@ -19,11 +19,14 @@ package devicemanager
import (
"context"
"fmt"
+ "io/ioutil"
"net"
"os"
"path/filepath"
"runtime"
"sort"
+ "strconv"
+ "strings"
"sync"
"time"
@@ -41,6 +44,7 @@ import (
"k8s.io/kubernetes/pkg/features"
"k8s.io/kubernetes/pkg/kubelet/checkpointmanager"
"k8s.io/kubernetes/pkg/kubelet/checkpointmanager/errors"
+ "k8s.io/kubernetes/pkg/kubelet/cm/cpuset"
"k8s.io/kubernetes/pkg/kubelet/cm/devicemanager/checkpoint"
"k8s.io/kubernetes/pkg/kubelet/cm/topologymanager"
"k8s.io/kubernetes/pkg/kubelet/config"
@@ -667,6 +671,75 @@ func (m *ManagerImpl) UpdateAllocatedDevices() {
m.allocatedDevices = m.podDevices.devices()
}
+//Given a list of isolated CPUs in 'devices', and the number of desired CPUs in 'needed',
+//return an ordered list of isolated CPUs such that the first 'needed' CPUs in the list
+//contain as many hyperthread sibling pairs as possible.
+func order_devices_by_sibling(devices sets.String, needed int) ([]string, error) {
+ var dev_lst []string
+ var single_lst []string
+ sibling_lst := make([]string, 0, int(devices.Len()))
+ _iterated_cpu := make(map[string]string)
+ get_sibling := func(cpu string, cpu_lst []string) string {
+ if cpu_lst[0] == cpu {
+ return cpu_lst[1]
+ } else {
+ return cpu_lst[0]
+ }
+ }
+ for cpu_id := range devices {
+ // If we've already found cpu_id as a sibling, skip it.
+ if _, ok := _iterated_cpu[cpu_id]; ok {
+ continue
+ }
+ devPath := fmt.Sprintf("/sys/devices/system/cpu/cpu%s/topology/thread_siblings_list", cpu_id)
+ dat, err := ioutil.ReadFile(devPath)
+ if err != nil {
+ return dev_lst, fmt.Errorf("Can't read cpu[%s] thread_siblings_list", cpu_id)
+ }
+ cpustring := strings.TrimSuffix(string(dat), "\n")
+ cpu_pair_set, err := cpuset.Parse(cpustring)
+ if err != nil {
+ return dev_lst, fmt.Errorf("Unable to parse thread_siblings_list[%s] string to cpuset", cpustring)
+ }
+ var cpu_pair_lst []string
+ for _, v := range cpu_pair_set.ToSlice() {
+ cpu_pair_lst = append(cpu_pair_lst, strconv.Itoa(v))
+ }
+ sibling_cpu_id := get_sibling(cpu_id, cpu_pair_lst)
+ if _, ok := devices[sibling_cpu_id]; ok {
+ sibling_lst = append(sibling_lst, cpu_id, sibling_cpu_id)
+ _iterated_cpu[sibling_cpu_id] = ""
+ } else {
+ single_lst = append(single_lst, cpu_id)
+ }
+ _iterated_cpu[cpu_id] = ""
+ }
+ if needed%2 == 0 {
+ dev_lst = append(sibling_lst, single_lst...)
+ } else {
+ if len(single_lst) > 1 {
+ _tmp_list := append(sibling_lst, single_lst[1:]...)
+ dev_lst = append(single_lst[0:1], _tmp_list...)
+ } else {
+ if len(single_lst) == 0 {
+ dev_lst = sibling_lst
+ } else {
+ dev_lst = append(single_lst, sibling_lst...)
+ }
+ }
+ }
+ //klog.Infof("needed=%d ordered_cpu_list=%v", needed, dev_lst)
+ return dev_lst, nil
+}
+func smt_enabled() bool {
+ dat, _ := ioutil.ReadFile("/sys/devices/system/cpu/smt/active")
+ state := strings.TrimSuffix(string(dat), "\n")
+ if state == "0" {
+ return false
+ }
+ return true
+}
+
// Returns list of device Ids we need to allocate with Allocate rpc call.
// Returns empty list in case we don't need to issue the Allocate rpc call.
func (m *ManagerImpl) devicesToAllocate(podUID, contName, resource string, required int, reusableDevices sets.String) (sets.String, error) {
@@ -702,7 +775,16 @@ func (m *ManagerImpl) devicesToAllocate(podUID, contName, resource string, requi
// Create a closure to help with device allocation
// Returns 'true' once no more devices need to be allocated.
allocateRemainingFrom := func(devices sets.String) bool {
- for device := range devices.Difference(allocated) {
+ availableDevices := devices.Difference(allocated).List()
+ // If we're dealing with isolcpus and SMT is enabled, reorder to group SMT siblings together.
+ if resource == "windriver.com/isolcpus" && len(devices) > 0 && smt_enabled() {
+ var err error
+ availableDevices, err = order_devices_by_sibling(devices.Difference(allocated), needed)
+ if err != nil {
+ klog.Errorf("error in order_devices_by_sibling: %v", err)
+ }
+ }
+ for _, device := range availableDevices {
m.allocatedDevices[resource].Insert(device)
allocated.Insert(device)
needed--
--
2.22.5

View File

@ -58,7 +58,8 @@ Patch4: kubelet-cpumanager-introduce-concept-of-isolated-CPU.patch
Patch5: kubeadm-create-platform-pods-with-zero-CPU-resources.patch
Patch6: enable-support-for-kubernetes-to-ignore-isolcpus.patch
Patch7: Revert-use-subpath-for-coredns-only-for-default-repo.patch
Patch8: kubernetes-make-isolcpus-allocation-SMT-aware.patch
Patch9: kubelet-sort-isolcpus-allocation-when-SMT-enabled.patch
# It obsoletes cadvisor but needs its source code (literally integrated)
@ -854,6 +855,8 @@ install in production.
%patch5 -p1
%patch6 -p1
%patch7 -p1
%patch8 -p1
%patch9 -p1
#src/k8s.io/kubernetes/pkg/util/certificates