Bug 241373 - ltp test gettimeofday02 fails: "Time is going backwards"
Summary: ltp test gettimeofday02 fails: "Time is going backwards"
Keywords:
Status: CLOSED NEXTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 6
Hardware: x86_64
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Brian Brock
URL:
Whiteboard:
Depends On:
Blocks: 427887
TreeView+ depends on / blocked
 
Reported: 2007-05-25 15:11 UTC by Zing
Modified: 2008-01-08 03:42 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2008-01-08 03:42:40 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)
dmesg output (24.30 KB, text/plain)
2007-05-25 15:11 UTC, Zing
no flags Details

Description Zing 2007-05-25 15:11:29 UTC
Description of problem:
the gettimeofday02 ltp test fails:
# ./gettimeofday02
gettimeofday02    0  INFO  :  checking if gettimeofday is monotonous, takes 30s
gettimeofday02    1  FAIL  :  Time is going backwards: old 1180105299.114454 vs
new 1180105299.114453!

Version-Release number of selected component (if applicable):
Fedora Core 6 x86_64 on an intel xeon dual processor blade (8843-E9U) in an IBM
Bladecenter H (8852-4XU)
kernel-2.6.20-1.2948.fc6.x86_64

How reproducible:
all the time on every gettimeofday02 run.

Steps to Reproduce:
1. compile gettimeofday02.c from the ltp test suite
2. run it
  
Additional Info:
# cat /proc/interrupts
           CPU0       CPU1       CPU2       CPU3
  0:    5304769          0          0          0   IO-APIC-edge      timer
  8:          0          0          0          0   IO-APIC-edge      rtc
 11:          0          0          0          0   IO-APIC-fasteoi   acpi
 16:     126505      11095          0          0   IO-APIC-fasteoi   uhci_hcd:usb1
 19:          0          0          0          0   IO-APIC-fasteoi   uhci_hcd:usb2
 24:      40656      33052     190008          0   IO-APIC-fasteoi   ioc0
 77:        102          0      54603        874   IO-APIC-fasteoi   eth0
NMI:          0          0          0          0
LOC:    5303930    5303872    5303797    5303221
ERR:          0

Comment 1 Zing 2007-05-25 15:11:29 UTC
Created attachment 155459 [details]
dmesg output

Comment 2 Chuck Ebbert 2007-06-22 21:52:25 UTC
Try using a different clock source.

I get:

$ ./gettimeofday02
gettimeofday02    0  INFO  :  checking if gettimeofday is monotonous, takes 30s
gettimeofday02    1  PASS  :  gettimeofday monotonous in 30 seconds

$ uname -rmp
2.6.20-1.2962.fc6 x86_64 x86_64

My dmesg:
time.c: Using 14.318180 MHz WALL HPET GTOD HPET/TSC timer.

Yours says:
time.c: Using 3.579545 MHz WALL PM GTOD PIT/TSC timer.



Comment 3 Zing 2007-06-26 13:54:56 UTC
Yes, that helped... clocksource of acpi_pm worked for me.

Comment 4 Jon Stanley 2008-01-08 01:47:13 UTC
(This is a mass-update to all current FC6 kernel bugs in NEW state)

Hello,

I'm reviewing this bug list as part of the kernel bug triage project, an attempt
to isolate current bugs in the Fedora kernel.

http://fedoraproject.org/wiki/KernelBugTriage

I am CC'ing myself to this bug, however this version of Fedora is no longer
maintained.

Please attempt to reproduce this bug with a current version of Fedora (presently
Fedora 8). If the bug no longer exists, please close the bug or I'll do so in a
few days if there is no further information lodged.

Thanks for using Fedora!

Comment 5 Zing 2008-01-08 03:42:40 UTC
F8 on a different blade, same type of hardware:

Time: tsc clocksource has been installed.

# uname -rmp
2.6.23.9-85.fc8 x86_64 x86_64
# ./gettimeofday02 
gettimeofday02    0  INFO  :  checking if gettimeofday is monotonous, takes 30s
gettimeofday02    1  PASS  :  gettimeofday monotonous in 30 seconds


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