Bug 213380
| Summary: | Clock going slow on kernel-xen | ||||||||||
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| Product: | [Fedora] Fedora | Reporter: | Ahmed Kamal <email.ahmedkamal> | ||||||||
| Component: | kernel-xen | Assignee: | Xen Maintainance List <xen-maint> | ||||||||
| Status: | CLOSED WONTFIX | QA Contact: | Virtualization Bugs <virt-bugs> | ||||||||
| Severity: | high | Docs Contact: | |||||||||
| Priority: | medium | ||||||||||
| Version: | 6 | CC: | bstein, gcosta | ||||||||
| Target Milestone: | --- | ||||||||||
| Target Release: | --- | ||||||||||
| Hardware: | i386 | ||||||||||
| OS: | Linux | ||||||||||
| Whiteboard: | |||||||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||||||
| Doc Text: | Story Points: | --- | |||||||||
| Clone Of: | Environment: | ||||||||||
| Last Closed: | 2008-02-26 23:37:38 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: | |||||||||||
| Attachments: |
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Description
Ahmed Kamal
2006-11-01 08:00:55 UTC
I cannot reproduce it on any of my systems. As it leaves me completely clueless (and most probably any other), it's a good idea to post your dmesg output for both boots, (xen and non-xen), as well as observing if there are any suspicious messages delivered while the system is running. Thanks Created attachment 142086 [details]
dmesg output on non-xen kernel
Created attachment 142087 [details]
dmesg output on xen kernel
Created attachment 142088 [details]
var/log/messages after booting my xen kernel
ok I added the needed attachements. Please do let me know, if you need further information (or devel testing on my hardware). I took a look, and the interesting parts seem to be apic and the "Calibrating Delay" line! ... Lots of other little differences as well! Didnt think they would be that different on the same hardware. Anyway, the problem still presists on the newer kernel (2.6.18-1.2849.fc6) Yes, this discrepancy between the xen and non-xen kernel is mostly normal. Next step is trying to find out what among it causes your problem ;-) One theory is that bios may be changing the cpu frequency for energy saving, and the xen hypervisor is not getting aware of it. Can you please check this, by completely disabling it at bios level ? Well, my BIOS had "CPU Frequency dynamically switchable" enabled, I disabled that, and made it "CPU Frequency Always High". Was so sure that was it, but unfortunately it didn't help! Not that I know anything about that, but the line "Calibrating delay using timer specific routine" seems too interesting and the numbers are different Update: Booting the Xen kernel with acpi=off, fixes the problem!!! It seems acpi was changing the CPU frequency without telling the clocking system! This way, it seems to me this problem is not really tied very much to my hardware! I'd be happy to provide any testing you'd require, because a laptop without acpi is not really useful change QA contact This report targets FC6, which is now end-of-life. Please re-test against Fedora 7 or later, and if the issue persists, open a new bug. Thanks |