The kernel shipped in Red Hat Enterprise Linux 5.6 includes several hundred bug fixes for and enhancements to the Linux kernel. For details concerning every bug fixed in and every enhancement added to the kernel for this release, refer to the kernel chapter in the Red Hat Enterprise Linux 5.6 Technical Notes
The most notable updates and additions to the kernel in this release include:
The tpm_tis driver for Trusted Platform Module (TPM) microcontrollers now automatically loads at boot time.
Support for the Actual Performance Clock Counter (APERF) and Maximum Qualified Performance Clock Counter (MPERF) Model-Specific Registers (MSRs) on AMD processors has been added.
Support for ITE-887x chips has been added.
VIO power management support for Power PC platforms has been added.
Support for the OSX and OSM OSA CHPID types in the qeth driver has been added
Advanced Linux Sound Architecture - High Definition Audio (ALSA-HDA) drivers have been updated.
SystemTap has been updated to version 1.3, providing an integrated compile-server client, automatic structure pretty-printing, faster and improved stack backtraces, and new sample scripts.
The Kernel Probes (kprobes) implementation has been updated.
The Per-task statistics interface (taskstats) has been updated.
Support for TCP cubic congested control has been added.
Support for the one packet scheduler in the networking stack has been added.
Two networking tuning parameters, ip_local_reserved_ports and ip_local_port_range parameter, have been added to allow users to reserve ports for third-party applications, and blacklist known offending ports.
The /proc/sys/vm/vm_devzero_optimized parameter has been added to skip ZERO_PAGE mmap of /dev/zero device.
Enhancements for iSNS, in the iSCSI Initiator, and the iSNS server have been added.
Kernel Application Binary Interface (kABI) has been updated.