- Issued:
- 2013-05-20
- Updated:
- 2013-05-20
RHBA-2013:0828 - Bug Fix Advisory
Synopsis
Red Hat Enterprise MRG Realtime 2.3 bug fix update
Type/Severity
Bug Fix Advisory
Red Hat Insights patch analysis
Identify and remediate systems affected by this advisory.
Topic
Updated Red Hat Enterprise MRG Realtime packages that fix several bugs are now
available for Red Hat Enterprise MRG 2.3.
Description
Red Hat Enterprise MRG (Messaging, Realtime, and Grid) is a next-generation IT
infrastructure for enterprise computing. MRG offers increased performance,
reliability, interoperability, and faster computing for enterprise customers.
MRG Realtime provides the highest levels of predictability for consistent
low-latency response times to meet the needs of time sensitive workloads. MRG
Realtime provides new levels of determinism by optimizing lengthy kernel code
paths to ensure that they do not become bottlenecks. This allows for better
prioritization of applications, resulting in consistent, predictable response
times for high-priority applications.
This update provides bug fixes for the following packages:
- The rt-setup package configures settings required by the Red Hat Enterprise
Linux real-time environment, such as creating the realtime group, adding
realtime user privileges to PAM (Pluggable Authentication Models), enabling the
configuration of kdump in real time, and disabling irqbalance by default.
- The rtctl package contains a set of scripts, which are used to manipulate the
scheduling priorities of groups of system threads.
Bug Fixes:
- The SLUB allocator in the kernel uses the deferred kfree() processing by
default. This caused latency spikes when the cpu_partial logic was executed to
reclaim the deferred kfree() blocks. Now, a slub_cpu_partial_off script is
executed at boot time. This script will traverse /sys/kernel/slab and write
zeros into any 'cpu_partial' entry found, effectively turning off the SLUB
cpu_partial logic and thus remove the noted latency spikes. (BZ#956776)
- The rt-setup package mounted the cpuset cgroup because the Realtime kernel
only supported that cgroup. Since the most recent Realtime kernel now supports
all the cgroups except the RT Group Scheduler, this custom cgroup mounting logic
was removed from rt-setup, and a package dependency for libcgroup was added. All
cgroups supported by the Realtime kernel are now mounted on boot by the
libcgroup startup code. (BZ#957802)
- The latest MRG 2.3 kernels have a different version name that contains a
stable sub-release number. This versioning prevented rtctl from matching the
correct configuration file, so rtctl resorted to using the default configuration
file, which could cause some threads to have unusual priorities. The routine
used to match configuration file names and kernel versions was changed to
address the special case present on MRG 2.3. The thread priorities are now
modified according to the correct configuration file or are left untouched in
cases where no suitable configuration file is found. (BZ#964190)
Users of the real-time capabilities of Red Hat Enterprise MRG 2.3, which is
layered on Red Hat Enterprise Linux 6, are advised to upgrade to these updated
packages, which fix these bugs.
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
- MRG Realtime 2 x86_64
Fixes
- BZ - 956776 - Update rt-setup to turn off SLUB cpu_partial logic at boot
- BZ - 957802 - remove cgroup related logic
CVEs
(none)
References
(none)
MRG Realtime 2
SRPM | |
---|---|
rt-setup-1.53-1.el6rt.src.rpm | SHA-256: 3c358547311ab6b5951eb1b19e3c4ec80d6dbaa5d9a25419af6deb2982f158cd |
rtctl-1.11-2.el6rt.src.rpm | SHA-256: bb7897ec503cafaa5422bcc9db49b98ce2375faaa973dafd74978ebdef07f85f |
x86_64 | |
rt-setup-1.53-1.el6rt.noarch.rpm | SHA-256: 68153781e3392058fa031e9af45b3890cd72a418362d7edd728e1574276379bc |
rtctl-1.11-2.el6rt.noarch.rpm | SHA-256: 154a6694d5faeb4a94d6b1b3c259c782aa6c114cb12ec0e2549da7f65c8b57d2 |
The Red Hat security contact is secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.