Red Hat ENTERPRISE LINUX 5.4 - TECHNICAL NOTES Manual page 147

• ACPI Performance and Throttling state (P- and T-state) change notifications were not being
handled correctly by the OSPM (Operating System-directed Power Management) driver. This
affected the Intel® Node Manager's ability to monitor and manage CPU power usage. The kernel's
processor_core code has been update to correct this issue.
• Problems were encountered with the Lenovo X61 (and other laptops which have a docking station
with a CD/DVD drive); if the machine was undocked after a CD/DVD had been mounted in the
docking station optical drive it would not be present when the machine was re-docked. The docking
driver has been updated in this release to correct the problem.
1.110.9.7. Architecture Specific Support
Updates specific to particular computer architectures.
1.110.9.7.1. i386
Kernel updates for i386 architectures.
• In a virtual environment, timekeeping for Red Hat Enterprise Linux 64-bit kernels can be
problematic, since time is kept by counting timer interrupts. De- and re-scheduling the virtual
machine can cause a delay in these interrupts, resulting in a timekeeping discrepancy. This kernel
release reconfigures the timekeeping algorithm to keep time based on a time-elapsed counter.
921
(BZ#463573 )
• It was found that, if their stacks exceed the combined size of ~4GB, 64-bit threaded applications
slowed down drastically in pthread_create(). This is because glibc uses MAP_32BIT to
allocate those stacks. As the use of MAP_32BIT is a legacy implementation, this update adds a new
flag (MAP_STACK mmap) to the kernel to avoid constraining 64-bit applications.
• The update includes a feature bit that encourages Time Stamp Clocks (TSCs) to keep running in
deep-C states. This bit NONSTOP_TSC acts in conjunction with CONSTANT_TSC. CONSTANT_TSC
indicates that the TSC runs at constant frequency irrespective of P/T- states, and NONSTOP_TSC
indicates that TSC does not stop in deep C-states.
• This update includes a patch to include asm-x86_64 headers in kernel-devel packages built on
or for i386, i486, i586 and i686 architectures.
• This update includes a fix to ensure that specifying memmap=X$Y as a boot parameter on i386
architectures yields a new BIOS map.
• This update adds a patch to correct a problem with the Non-Maskable Interrupt (NMI) that appeared
in previous kernel releases. The problem appeared to affect various Intel® processors and caused
the system to report the NMI watchdog was 'stuck'. New parameters in the NMI code correct this
926
issue. (BZ#500892
• This release re-introduces PCI Domain support for HP xw9400 and xw9300 systems.
927
(BZ#474891 )
• Functionality has been corrected to export module powernow-k8 parameters to /sys/modules.
This information was previously not
1.110.9.7.2. x86_64
Kernel updates for x86_64 architectures.
(BZ#464500
)
exported.(BZ#492010
(BZ#487567
(BZ#485181
923
(BZ#474091 )
924
(BZ#491775 )
925
)
928
)
RHSA-2009:1243
919
)
920
)
922
(BZ#459321 )
129