Bug 394581 - Enforce report_lost_ticks boot time parameter in time.c
Summary: Enforce report_lost_ticks boot time parameter in time.c
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel
Version: 5.1
Hardware: x86_64
OS: Linux
Target Milestone: ---
: ---
Assignee: Prarit Bhargava
QA Contact: Martin Jenner
Depends On:
TreeView+ depends on / blocked
Reported: 2007-11-21 16:47 UTC by John Sobecki
Modified: 2008-05-21 15:02 UTC (History)
3 users (show)

Clone Of:
Last Closed: 2008-05-21 15:02:14 UTC

Attachments (Terms of Use)
enforce report_lost_ticks (793 bytes, text/x-patch)
2007-11-21 16:47 UTC, John Sobecki
no flags Details
RHEL5 fix for this issue (1.18 KB, patch)
2007-11-27 18:48 UTC, Prarit Bhargava
no flags Details | Diff

External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2008:0314 normal SHIPPED_LIVE Updated kernel packages for Red Hat Enterprise Linux 5.2 2008-05-20 18:43:34 UTC

Description John Sobecki 2007-11-21 16:47:49 UTC
Description of problem:

During high database load testing (Oracle OLT) the kernel issues both of
these lost tick related warning messages:

1) kernel: warning: many lost ticks.
   kernel: Your time source seems to be instable or some driver is 
           hogging interupts

2)  kernel: Losing some ticks... checking if CPU frequency changed.

Version-Release number of selected component (if applicable):


How reproducible:

Under large Oracle OLT load testing, with 1000+ processes, this can
be reproduced 100% of the time. 

Steps to Reproduce:
1. Create Oracle DB
2. Load OLT test kit (available at htto://oss.oracle.com/projects/olt)
3. Run large load with 1000+ processes
Actual results:

Machine will slow and kick out multiple lost ticks messages.
Expected results:

Only print lost ticks messages if booted with 'report_lost_ticks'.

Additional info:

Customer noticed this after they switched from SLES9 to RHEL5; in SLES9
there is only one place where lost ticks warnings are printed, and it
includes an if (report_lost_ticks) check before the code block.

Comment 1 John Sobecki 2007-11-21 16:47:49 UTC
Created attachment 266131 [details]
enforce report_lost_ticks

Comment 4 Prarit Bhargava 2007-11-27 18:48:50 UTC
Created attachment 270051 [details]
RHEL5 fix for this issue

Updated patch.

Comment 5 RHEL Product and Program Management 2007-12-06 00:15:33 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

Comment 7 Don Zickus 2007-12-17 19:37:42 UTC
in 2.6.18-61.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5

Comment 10 errata-xmlrpc 2008-05-21 15:02:14 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.


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