RHBA-2013:0367 - Bug Fix Advisory

Topic

Updated irqbalance packages that fix multiple bugs and add various enhancements
are now available for Red Hat Enterprise Linux 6.

Description

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)

This update also fixes the following bugs:

• 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. (BZ#813078)

• 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. (BZ#843379)

• 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. (BZ#860627)

All users of irqbalance are advised to upgrade to these updated packages, which
fix these bugs and add these enhancements.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386

Fixes

• BZ - 813078 - Document use of IRQBALANCE_BANNED_INTERRUPTS and give examples for it and for IRQBALANCE_BANNED_CPUS
• BZ - 860627 - irqbalance is not being daemonize

CVEs

(none)

References

(none)