Bug 690134 - Time runs too fast in a VM on processors with > 4GHZ freq [rhel-5.6.z]
Summary: Time runs too fast in a VM on processors with > 4GHZ freq [rhel-5.6.z]
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel
Version: 5.7
Hardware: All
OS: Linux
urgent
high
Target Milestone: rc
: ---
Assignee: Zachary Amsden
QA Contact: Red Hat Kernel QE team
URL:
Whiteboard:
Depends On: 673242
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-03-23 12:14 UTC by RHEL Program Management
Modified: 2013-01-11 03:53 UTC (History)
17 users (show)

Fixed In Version: kernel-2.6.18-238.10.1.el5
Doc Type: Bug Fix
Doc Text:
Previously, on VMware, the time ran too fast on virtual machines with more than 4GHz TSC (Time Step Counter) processor frequency if they were using PIT/TSC based timekeeping. This was due to a calculation bug in the get_hypervisor_cycles_per_sec function. This update fixes the calculation, and timekeeping works correctly for such virtual machines
Clone Of:
Environment:
Last Closed: 2011-05-31 14:08:52 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2011:0833 0 normal SHIPPED_LIVE Important: kernel security and bug fix update 2011-05-31 14:05:42 UTC

Description RHEL Program Management 2011-03-23 12:14:26 UTC 
This bug has been copied from bug #673242 and has been proposed
to be backported to 5.6 z-stream (EUS).
Comment 3 Phillip Lougher 2011-04-15 15:05:09 UTC 
in kernel-2.6.18-238.10.1.el5

linux-2.6-virt-hypervisor-overflow-fix-for-clocks-4ghz.patch
Comment 6 errata-xmlrpc 2011-05-31 14:08:52 UTC 
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-0833.html
Comment 7 Martin Prpič 2011-06-02 13:28:15 UTC 
    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
Previously, on VMware, the time ran too fast on virtual machines with more than 4GHz TSC (Time Step Counter) processor frequency if they were using PIT/TSC based timekeeping. This was due to a calculation bug in the get_hypervisor_cycles_per_sec function. This update fixes the calculation, and timekeeping works correctly for such virtual machines
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