Merge pull request #29663 from abhibhaw/issue-29524

feat: Documents effects on secrets when memory swap is enabled

Author: k8s-ci-robot

content/en/docs/concepts/architecture/nodes.md

@@ -451,6 +451,11 @@ the kubelet, and the `--fail-swap-on` command line flag or `failSwapOn`
 [configuration setting](/docs/reference/config-api/kubelet-config.v1beta1/#kubelet-config-k8s-io-v1beta1-KubeletConfiguration)
 must be set to false.
 
+{{< warning >}}
+When the memory swap feature is turned on, Kubernetes data such as the content
+of Secret objects that were written to tmpfs now could be swapped to disk.
+{{< /warning >}}
+
 A user can also optionally configure `memorySwap.swapBehavior` in order to
 specify how a node will use swap memory. For example,