kubectl get node <nodename> -o yaml | grep "gocrane.io/memory-compression"

# Confirm zram device initialization.
# zramctl
NAME       ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT
/dev/zram0 lzo-rle       3.6G   4K   74B   12K       2 [SWAP]

# Confirm settings for swap.
# free -h
              total        used        free      shared  buff/cache   available
Mem:          3.6Gi       441Mi       134Mi       5.0Mi       3.0Gi       2.9Gi
Swap:         3.6Gi       0.0Ki       3.6Gi

# sysctl vm.force_swappiness
vm.force_swappiness = 1

# QosAgent will set an annotation for the pod with memory compression enabled.
kubectl get pods -l app=memory-stress -o jsonpath="{.items[0].metadata.annotations.gocrane\\.io\\/memory-compression}"

# zramctl
NAME       ALGORITHM DISKSIZE  DATA  COMPR TOTAL STREAMS MOUNTPOINT
/dev/zram0 lzo-rle       3.6G  163M 913.9K  1.5M       2 [SWAP]

# free -h
              total        used        free      shared  buff/cache   available
Mem:          3.6Gi       1.4Gi       562Mi       5.0Mi       1.7Gi       1.9Gi
Swap:         3.6Gi       163Mi       3.4Gi

#Check memory.zram.{raw_in_bytes,usage_in_bytes} in cgroup (usually in /sys/fs/cgroup/memory/) to see the amount of memory compressed in the pod, the size of memory after compression, and the difference, which indicates the memory saved.
cat memory.zram.{raw_in_bytes,usage_in_bytes}
170659840
934001

#Calculate the difference to obtain the size of memory saved. In the example, 170Mi of memory was saved.
cat memory.zram.{raw_in_bytes,usage_in_bytes} | awk 'NR==1{raw=$1} NR==2{compressed=$2} END{ print raw - compress }'
170659840