Installation guide

Release Notes

5.3. PowerPC Architectures

• CPUFreq, the kernel subsystem that scales CPU frequency and voltage, has been updated with

improved support for Cell Processors. This update implements a Synergistic Processing Unit (SPU)

aware CPUFreq governor that enhances the power management of Cell processors.

• Error Detection and Correction (EDAC) is now supported on the Cell Broadband Engine Architecture

in Red Hat Enterprise Linux 5.3. To enable EDAC, use the command: modprobe cell_edac

To check this module has been added to your running kernel, check /var/log/dmesg for output like

the following:

EDAC MC: Ver: 2.0.1 Oct 4 2008

EDAC MC0: Giving out device to cell_edac MIC: DEV cbe-mic

EDAC MC1: Giving out device to cell_edac MIC: DEV cbe-mic

If correctable memory errors are encountered, the following message will be returned to the

console:

EDAC MC0: CE page 0xeff, offset 0x5700, grain 0, syndrome 0x51, row 0,

channel

0, label "":

• Debugging with hardware watchpoints using a variable that is shared between multiple threads was

causing the GNU Debugger (GDB) to erratically miss trigger events. The kernel has been updated to

allow GDB to consistently receive the watchpoint triggers, improving the reliability of the debugging

session.

5.4. x86_64 Architectures

• kprobe-booster is now supported on the ia64 and x86_64 architectures, allowing users to probe

kernel events much faster. This feature will also decrease the overhead caused by probing tools

(e.g. SystemTap and Kprobes) on servers running on 64-bit architecture.

• Support has been added to the kernel for the _PTC (Processor Throttling Control), _TSS (Throttling

Supported States) and _TPC (Throttling Present Capabilities) objects. This support, which is

part of the Advance Configuration and Power Interface specification (ACPI) provides improved

management of processor throttling.

5.5. s390x Architectures

• In zipl.conf, parameters enclosed with double quotes inside of single quotes (ie

parameters='vmhalt="LOGOFF"') were being parsed incorrectly. Consequently, installing the

kernel-kdump package may have failed, resulting in the error:

grubby fatal error: unable to find a suitable template