Bug 305011

Summary: [RHEL 5.1.z]: Tick divider bugs on x86_64
Product: Red Hat Enterprise Linux 5 Reporter: Chris Lalancette <clalance>
Component: kernelAssignee: Chris Lalancette <clalance>
Status: CLOSED ERRATA QA Contact: Martin Jenner <mjenner>
Severity: medium Docs Contact:
Priority: urgent    
Version: 5.1CC: alan, anton, bmaly, dhecht, dhoward, dzickus, garrett, marcobillpeter, prarit
Target Milestone: ---Keywords: ZStream
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: RHSA-2007-0993 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2007-11-29 14:46:55 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 315471    
Attachments:
Description Flags
Patch to fix some of the tick divider problems none

Description Chris Lalancette 2007-09-25 13:16:34 UTC 
Description of problem:
On x86_64, the tick divider patch seems to have multiple bugs, which cause
problems on VMware ESX server.  In particular, because not all of the clocks are
being properly divided, it needs many more interrupts than a kernel re-compiled
to 100HZ would, and can cause time drift.  The problems identified so far are:

1)  It does not set the local APIC to the "divided" value; it leaves it at the
undivided value.
2)  It does not properly account for lost ticks when using PM-timer (it thinks
there are more lost ticks than there actually are).
3)  It does not properly account for lost ticks when using TSC.

A preliminary patch (based on input from VMware) is attached.
Comment 1 Chris Lalancette 2007-09-25 13:16:35 UTC 
Created attachment 205451 [details]
Patch to fix some of the tick divider problems
Comment 3 Alan Cox 2007-10-02 12:37:28 UTC 
Looks sane on a first glance
Comment 4 RHEL Program Management 2007-10-02 19:54:26 UTC 
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.
Comment 6 Anton Arapov 2007-10-24 20:54:57 UTC 
A patch for this issue has been included in build 2.6.18-53.1.2
Comment 8 Mike Gahagan 2007-10-30 21:57:03 UTC 
confirmed fix is in the -53.1.2 kernel, looks to have already been verified by
customer.
Comment 9 Mike Gahagan 2007-11-01 16:24:19 UTC 
setting back to on_qa as this will go out to customers in a later erratum.
Comment 11 errata-xmlrpc 2007-11-29 14:46:55 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 the 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-2007-0993.html