Red Hat unveiled Few days ago the release of the new version of Red Hat Enterprise Linux 8.4. The 8.x branch, which will be supported until at least 2029, is evolving according to a new predictable development cycle, which involves the formation of releases every six months at a predetermined time.
RHEL's new product development cycle spans multiple layers, including Fedora as a springboard for new capabilities, CentOS Stream for accessing packages for the next interim release of RHEL (RHEL mobile variant), a minimalist universal base image (UBI, Universal Base Image) to run applications in isolated containers and RHEL developer subscription to use RHEL for free during development.
What's New in Red Hat Enterprise Linux 8.4
In this new version added experimental support for multiprotocol label switching technology (MPLS) to route packets using multiprotocol label switching. Using MPLS, for example, allows you to define filters through the tc utility to control packets coming from specific ports or associated with a specific type of traffic.
We can also find that the support for proactive compacting mechanism of memory pages in the background (proactive compaction), which allows to increase the number of large memory pages (huge pages, pages larger than 4KB) available to the kernel. Automatic background packing (defragmentation) at the cost of minimal overhead allows 70-80 times lower latency when allocating large memory pages compared to the previously used on-demand packing mechanism, which is started directly when allocating a big page. By default, proactive compaction mode is disabled for now.
A new slab memory controller is used, which is notable for the transfer of slab accounting from the memory page level to the kernel object level, making it possible to share slab pages across different cgroups, rather than allocating separate slab caches for each cgroup. The proposed approach allows to increase the efficiency of the use of slab, reduce the size of the memory used for slab by 30-45%, significantly reduce the total memory consumption by the kernel and reduce memory fragmentation.
Also stable support provided for the XDP subsystem (eXpress Data Path), which allows you to manipulate network packets in the stage before they are processed by the Linux kernel network stack. For example, with XDP, you can run BPF programs at the network driver level with direct access to the DMA packet buffer and before the network stack allocates skbuff.
Added the ability to return memory not used by virtual machines to the hypervisor. The virtio_balloon handler should be used to return memory pages on the VM side.
Realtime components (kernel-rt) are in sync with kernel patch set v5.10-rt7 (previously 5.6.14-rt7). It includes a background storage process that monitors threads when launching highly responsive applications. When dormant threads are detected, a temporary change is made to the SCHED_DEADLINE scheduling policy and additional CPU time is allocated to the thread.
As well added a kernel module with support for the EDAC mechanism (Error Detection and Correction), provided on XNUMXth and XNUMXth generation Intel Core processors, to detect and correct errors in the ECC memory and the PCI bus.
The fapolicyd framework, which allows you to determine which programs can be launched by a certain user and which cannot, has been added to support the Integrity Measurement Architecture (Integrity Measurement Architecture) and has been implemented to record RPM package updates.
For those who are interested in being able to obtain the installation images, they should know that they are only available to registered users on the portal.
If you want to know more about it, you can check the details In the following link.