7.93. irqbalance

Updated irqbalance packages that fix multiple bugs and add various enhancements are now available for Red Hat Enterprise Linux 6.
The irqbalance packages provide a daemon that evenly distributes interrupt request (IRQ) load across multiple CPUs for enhanced performance.


The irqbalance packages have been upgraded to upstream version 1.0.4, which provides a number of bug fixes and enhancements over the previous version. Among other changes, the irqbalance daemon has been enhanced to support multiple MSI-X interrupts for PCI devices, which significantly boosts speed of devices producing high-rate interrupts, such as network cards. Also, the irqbalance logic has been modified to consider PCI bus topology when making IRQ mapping decisions. (BZ#789946)

Bug Fixes

The irqbalance(1) man page did not contain documentation for the IRQBALANCE_BANNED_CPUS environment variable. This update adds the extensive documentation to this man page.
The irqbalance daemon assigns each interrupt source in the system to a "class", which represents the type of the device (for example Networking, Storage or Media). Previously, irqbalance used the IRQ handler names from the /proc/interrupts file to decide the source class, which caused irqbalance to not recognize network interrupts correctly. As a consequence, systems that use NIC biosdevnames did not have their hardware interrupts distributed and pinned as expected. With this update, the device classification mechanism has been improved, which ensures a better interrupts distribution.
Previously, the irqbalance init script started the irqbalance daemon with the "--foreground" option, which caused irqbalance to become unresponsive. With this update, the "--foreground" option has been removed from the init script and irqbalance now starts as expected.
All users of irqbalance are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.