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.

Example log for a 3 cpu isolcpus request:

2022-02-11T16:27:50.345 controller-0 kubelet[1531574]: info I0211
16:27:50.345529 1531574 manager.go:741] order_devices_by_sibling:
needed=3, smtpairs=[4 5 6 7 10 11], singletons=[8 12],
order=[8 4 5 6 7 10 11 12]

The specific host with SMT enabled has this topology:
LOGICAL CPU TOPOLOGY:
   cpu_id : 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
socket_id : 0 0 0 0 0 0 0 0 0 0  0  0  0  0  0  0
  core_id : 0 0 1 1 2 2 3 3 4 4  5  5  6  6  7  7
thread_id : 0 1 0 1 0 1 0 1 0 1  0  1  0  1  0  1

Before cpu allocation, host has Isolated_free: 4-8,10-12.
New pod gets the following isolcpus cpuset: 4-5,8.

Test Plan: (On AIO-SX, SMT enabled)

PASS: Verify cpu sort order for even needed and no singletons
PASS: Verify cpu sort order for odd  needed and no singletons
PASS: Verify cpu sort order for even needed and singletons
PASS: Verify cpu sort order for odd  needed and singletons

Story: 2008760
Task: 44190

Signed-off-by: Jim Gauld <james.gauld@windriver.com>
Change-Id: I1d743f80925b35ecee7936c12b0f4328f83b7eb2

kubernetes/kubernetes-1.21.8/centos/files/kubelet-sort-isolcpus-allocation-when-SMT-enabled.patch

@@ -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
+

kubernetes/kubernetes-1.21.8/centos/kubernetes.spec

@@ -62,6 +62,7 @@ Patch6: enable-support-for-kubernetes-to-ignore-isolcpus.patch
 Patch7: Revert-use-subpath-for-coredns-only-for-default-repo.patch
 Patch8: Change-log-level-to-Debug.patch
 Patch9: kubernetes-make-isolcpus-allocation-SMT-aware.patch
+Patch10: kubelet-sort-isolcpus-allocation-when-SMT-enabled.patch
 
 # It obsoletes cadvisor but needs its source code (literally integrated)
 Obsoletes:      cadvisor
@@ -858,6 +859,7 @@ install in production.
 %patch7 -p1
 %patch8 -p1
 %patch9 -p1
+%patch10 -p1
 
 #src/k8s.io/kubernetes/pkg/util/certificates
 # Patch the code to remove eliptic.P224 support