- Faster mount detection for linux kernel 5.10+ using openat2 speeding up pod churn rates. On Kernel versions less 5.10, it will fallback to using the original way of detecting mount points i.e by parsing /proc/mounts. ([#109217](https://github.com/kubernetes/kubernetes/pull/109217), [@manugupt1](https://github.com/manugupt1))...

  
  When the feature gate is enabled, kubelet ignores errors that happens during setting the following sysctl values: `vm.overcommit_memory`, `vm.panic_on_oom`, `kernel.panic`, `kernel.panic_on_oops`, `kernel.keys.root_maxkeys`, `kernel.keys.root_maxbytes`. (These sysctl values for the host, not for the containers)
  
  kubelet also ignores an error during opening `/dev/kmsg`.

    * Add hugepages monitoring support
    * Fix incorrect CPU usage metrics with 4.7 kernel
    * Add tmpfs monitoring support
* Support for Huge pages in empty_dir volume plugin ([#50072](https://github.com/kubernetes/kubernetes/pull/50072), [@squall0gd](https://github.com/squall0gd))
    * [Huge pages](https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt) can now be used with empty dir volume plugin.

  // https://access.redhat.com/documentation/en-us/red_hat_subscription_management/1/html/rhsm/uuid
  optional string systemUUID = 2;

  // Boot ID reported by the node.
  optional string bootID = 3;

  // Kernel Version reported by the node from 'uname -r' (e.g. 3.16.0-0.bpo.4-amd64).
  optional string kernelVersion = 4;

  // OS Image reported by the node from /etc/os-release (e.g. Debian GNU/Linux 7 (wheezy)).

- `kube-proxy`: Added an option/flag for configuring the `nf_conntrack_tcp_be_liberal` sysctl (in the kernel's netfilter conntrack subsystem).  When enabled, `kube-proxy` will not install the `DROP` rule for invalid conntrack states, which currently breaks users of asymmetric routing. ([#120354](https://github.com/kubernetes/kubernetes/pull/120354), [@a...

    * Add hugepages monitoring support
    * Fix incorrect CPU usage metrics with 4.7 kernel
    * Add tmpfs monitoring support
* Support for Huge pages in empty_dir volume plugin ([#50072](https://github.com/kubernetes/kubernetes/pull/50072), [@squall0gd](https://github.com/squall0gd))
    * [Huge pages](https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt) can now be used with empty dir volume plugin.

- Add --permit-address-sharing flag to `kube-apiserver` to listen with `SO_REUSEADDR`. While allowing to listen on wildcard IPs like 0.0.0.0 and specific IPs in parallel, it avoids waiting for the kernel to release socket in `TIME_WAIT` state, and hence, considerably reducing `kube-apiserver` restart times under certain conditions. ([#93861](https://github.com/kubernetes/kubernetes/pull/93861), [@sttts](https://github.com/sttts))

  
  Enabling seccomp for your workload can have a negative performance impact depending on the kernel and container runtime version in use.
  

- SCTP support in API objects (Pod, Service, NetworkPolicy) is now GA.
  Note that this has no effect on whether SCTP is enabled on nodes at the kernel level,
  and note that some cloud platforms and network plugins do not support SCTP traffic. ([#95566](https://github.com/kubernetes/kubernetes/pull/95566), [@danwinship](https://github.com/danwinship)) [SIG Apps and Network]

- kubeadm will now not fail preflight checks when running on >= 5.0 Linux kernel ([#74355](https://github.com/kubernetes/kubernetes/pull/74355), [@brb](https://github.com/brb))