Merge pull request #44240 from my-git9/memory-available-cgroupv2

[zh-cn] sync memory-available-cgroupv2.sh

content/zh-cn/examples/admin/resource/memory-available-cgroupv2.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+# 此脚本重现了 kubelet 相对于 kubepods cgroup 计算 memory.available 的操作
+
+# 当前内存使用情况
+memory_capacity_in_kb=$(cat /proc/meminfo | grep MemTotal | awk '{print $2}')
+memory_capacity_in_bytes=$((memory_capacity_in_kb * 1024))
+memory_usage_in_bytes=$(cat /sys/fs/cgroup/kubepods.slice/memory.current)
+memory_total_inactive_file=$(cat /sys/fs/cgroup/kubepods.slice/memory.stat | grep inactive_file | awk '{print $2}')
+
+memory_working_set=${memory_usage_in_bytes}
+if [ "$memory_working_set" -lt "$memory_total_inactive_file" ];
+then
+    memory_working_set=0
+else
+    memory_working_set=$((memory_usage_in_bytes - memory_total_inactive_file))
+fi
+
+memory_available_in_bytes=$((memory_capacity_in_bytes - memory_working_set))
+memory_available_in_kb=$((memory_available_in_bytes / 1024))
+memory_available_in_mb=$((memory_available_in_kb / 1024))
+
+echo "memory.capacity_in_bytes $memory_capacity_in_bytes"
+echo "memory.usage_in_bytes $memory_usage_in_bytes"
+echo "memory.total_inactive_file $memory_total_inactive_file"
+echo "memory.working_set $memory_working_set"
+echo "memory.available_in_bytes $memory_available_in_bytes"
+echo "memory.available_in_kb $memory_available_in_kb"
+echo "memory.available_in_mb $memory_available_in_mb"