| Summary: | kworkers consume lots of CPU (ath5k) | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | David Nečas <yeti> |
| Component: | kernel | Assignee: | John W. Linville <linville> |
| Status: | CLOSED WONTFIX | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 15 | CC: | clancy.kieran+redhat, gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda, me, mickflemm |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2012-07-11 17:53:43 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
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Description
David Nečas
2011-10-28 20:27:36 UTC
> Oct 28 22:14:40 smut kernel: [28916.356033] ath5k phy0: gain calibration
timeout (2447MHz)
Calibration does a lot of busy loops.. I think we can change some mdelays into sleeps without problems now that reset is called from process context.
Old logs do not contain the calibration timeout messages. Has the ath5k calibration changed and this is a consequence? I can try to find the exact kernel package where the problem appeared (taking older kernels pkgs from koji) if it helps. The only method to test a kernel seems to be to boot it and wait a few minutes to see if anything bad happens so bisection will take time but it's possible. Can you try using fast channel switching ? There is a module option for that fastchanswitch, set it to true when loading the module and see if you get better results. As for the udelay, I think we should switch to usleep_range for most stuff we use and in general we don't need accuracy e.g. when waiting for analog parts to settle, just a rough estimate. I already have some patches for calibration pending so I'll do the switch and see how it goes... I added `options ath5k fastchanswitch', enabled wireless, rebooted (to get to a defined state) and it seemed fixed. But then I removed the option again, rebooted and still did not observe any problems - they miraculously disappeared. All with the same 2.6.40.6-0.fc15.x86_64 kernel. So I don't know what's going on here. Can the calibration be influenced by other wifi devices around? If it is so it makes the problem non-detereministic (when I experienced it it persisted through several reboots). I'm seeing this too. Related to bug 638943? Is this still an issue on 2.6.43/3.3? Fedora 15 has reached it's end of life as of June 26, 2012. As a result, we will not be fixing any remaining bugs found in Fedora 15. In the event that you have upgraded to a newer release and the bug you reported is still present, please reopen the bug and set the version field to the newest release you have encountered the issue with. Before doing so, please ensure you are testing the latest kernel update in that release and attach any new and relevant information you may have gathered. Thank you for taking the time to file a report. We hope newer versions of Fedora suit your needs. |