Bug 679905 - CPU scheduler load balancer is broken (cgroups)
Summary: CPU scheduler load balancer is broken (cgroups)
Keywords:
Status: CLOSED UPSTREAM
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: kernel
Version: 6.2
Hardware: All
OS: Linux
unspecified
unspecified
Target Milestone: rc
: ---
Assignee: Rik van Riel
QA Contact: Red Hat Kernel QE team
URL:
Whiteboard:
Depends On: 672113
Blocks: 767187
TreeView+ depends on / blocked
 
Reported: 2011-02-23 20:11 UTC by Rik van Riel
Modified: 2013-01-09 23:35 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 672113
Environment:
Last Closed: 2011-12-12 17:22:14 UTC
Target Upstream Version:

Attachments (Terms of Use)
Add an attachment (proposed patch, testcase, etc.)

Description Rik van Riel 2011-02-23 20:11:41 UTC 
+++ This bug was initially created as a clone of Bug #672113 +++

Description of problem:

The CPU scheduler's load balancer in RHEL 6 is broken. With my PLE test, it was common for 1 4-CPU virtual machine to get around 300% CPU time, while the other 4-CPU virtual machine (contending for the same 4 CPUs) only got about 100% CPU time.

Upstream has several patches to fix load balancing.  I would like to try backporting those to RHEL 6 to see if that resolves the issues observed.

Note that CPU load balancing with cgroups will probably still be broken, even with those changesets applied; that is another bug alltogether.

(This bug is to track not-yet-materialized cgroups load balancing fixes from upstream)
Note You need to log in before you can comment on or make changes to this bug.