- 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`.

  // 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.
  

- Changes behaviour of kube-proxy start; does not attempt to set specific `sysctl` values (which does not work in recent Kernel versions anymore in non-init namespaces), when the current sysctl values are already set higher. ([#103174](https://github.com/kubernetes/kubernetes/pull/103174), [@Napsty](https://github.com/Napsty))

- Clarified the CFS quota as 100ms in the code comments and set the minimum `cpuCFSQuotaPeriod` to 1ms to match Linux kernel expectations. ([#112123](https://github.com/kubernetes/kubernetes/pull/112123), [@paskal](https://github.com/paskal))

- Publishing kube-proxy metrics for Windows kernel-mode ([#106581](https://github.com/kubernetes/kubernetes/pull/106581), [@knabben](https://github.com/knabben))