Bug 10986

Summary: Hires timers do not work in 2.6.25.9
Product: Timers Reporter: Rus (harbour)
Component: Interval TimersAssignee: timers_interval-timers
Status: CLOSED DOCUMENTED    
Severity: normal CC: yakui.zhao
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 2.6.25.9 SMP Subsystem:
Regression: --- Bisected commit-id:
Attachments: Boot log (dmesg)
/proc/timer_list

Description Rus 2008-06-26 03:36:29 UTC 
Latest working kernel version: do not know
Earliest failing kernel version: do not know
Distribution: slackware-current
Hardware Environment: Laptop Acer Ferrari 1100 (AMD X2 / ATI SB600 / 4GB RAM)
Software Environment: Plain Linus 2.6.25.9
Problem Description: Systems has HPET timer and LAPIC's, but dmesg contains :

...
Clockevents: could not switch to one-shot mode:<6>Clockevents: could not switch 
to one-shot mode: lapic is not functional.
Could not switch to high resolution mode on CPU 1
 lapic is not functional.
Could not switch to high resolution mode on CPU 0
...

Tried with [no success ] boot option 'clocksource=hpet' - dmesg still complains about 'not functional lapic', even if hpet is explicitly selected as main clock source.
 Can supply any additional info - dmesg is attached.

Steps to reproduce: Boot the kernel
Comment 1 Rus 2008-06-26 03:37:12 UTC 
Created attachment 16635 [details]
Boot log (dmesg)
Comment 2 Rus 2008-06-26 03:40:04 UTC 
Created attachment 16636 [details]
/proc/timer_list
Comment 3 Thomas Gleixner 2008-06-26 05:12:21 UTC 
AMD C1E detected late.  Force timer broadcast.

We can not enable high resolution timers with C1E, as local APIC timers stop in C1E state.

There is a patch pending for .27 which provides support for C1E and highres timers / dynticks.

Thanks,
       tglx
Comment 4 ykzhao 2008-08-13 19:31:46 UTC 
Hi, Thomas
   Will you please attach the patch pending for .27 which provides support for C1E and highres timers?
   thanks.
Comment 5 Thomas Gleixner 2008-08-14 04:27:29 UTC 
The patch is merged into Linus tree already. It's hard to back port as it depends on other large scale patches.