Bug 832815
| Summary: | irqbalance does not honor affinity_hint values from drivers loaded after it starts | ||||||
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| Product: | [Fedora] Fedora | Reporter: | Andrew J. Schorr <aschorr> | ||||
| Component: | irqbalance | Assignee: | Petr Holasek <pholasek> | ||||
| Status: | CLOSED ERRATA | QA Contact: | Fedora Extras Quality Assurance <extras-qa> | ||||
| Severity: | medium | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 16 | CC: | anton, dhoward, nhorman, pholasek | ||||
| Target Milestone: | --- | ||||||
| Target Release: | --- | ||||||
| Hardware: | Unspecified | ||||||
| OS: | Unspecified | ||||||
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| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2012-09-17 23:55:04 UTC | Type: | Bug | ||||
| 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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Hello, I've escalated this issue upstream: http://code.google.com/p/irqbalance/issues/detail?id=32 Could you please test patch posted by Neil? thanks, Petr H Hi, This patch did not work for me. While this solution seems more elegant in principle, I think there's a race condition that is causing it to fail. Perhaps the irq is being instantiated and triggering a rescan before the driver gets a chance to set the affinity_hint. Regards, Andy The rescan will have a minimum period of 10 seconds, while the time between registering an irq and settings its affinity hint will be measured in microseconds. So if you're getting a consistent failure of this patch, then I think something else is going on. Can you tell me: 1) What the affinity_hint of the irq in question is 2) What irqbalance sets that irqs smp_affinity to 3) What the irqbalance daemons hintpolicy is Andrew, any news? irqbalance-1.0.3-6.fc18 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/irqbalance-1.0.3-6.fc18 Package irqbalance-1.0.3-6.fc18: * should fix your issue, * was pushed to the Fedora 18 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing irqbalance-1.0.3-6.fc18' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2012-12570/irqbalance-1.0.3-6.fc18 then log in and leave karma (feedback). irqbalance-1.0.3-7.fc18 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/irqbalance-1.0.3-7.fc18 irqbalance-1.0.3-6.fc17 has been submitted as an update for Fedora 17. https://admin.fedoraproject.org/updates/irqbalance-1.0.3-6.fc17 irqbalance-1.0.3-8.fc18 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/irqbalance-1.0.3-8.fc18 irqbalance-1.0.3-8.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report. irqbalance-1.0.3-6.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report. |
Created attachment 592442 [details] Patch the irqbalance.service to start after network.target so network driver affinity_hint values will be honored. Description of problem: irqbalance should honor affinity_hint values set by various drivers. Since it reads the affinity_hint values only once at startup (unless there's a cpu hotplug event), it is important that irqbalance start after the drivers have been loaded. The irqbalance.service file says "After=syslog.target"; as a result, irqbalance may start before drivers have had a chance to call irq_set_affinity_hint. For network drivers, this problem can be solved by adding After=network.target. Version-Release number of selected component (if applicable): irqbalance-1.0.3-3.fc16.x86_64 How reproducible: Boot up the system. If irqbalance starts too early, the /proc/irq/*/smp_affinity values will not be consistent with the /proc/irq/*/affinity_hint values. Steps to Reproduce: 1. Configure the system with a driver that sets affinity_hint values. 2. Reboot the system. 3. Observer that the /proc/irq/*/smp_affinity values may not be consistent with the /proc/irq/*/affinity_hint values. Actual results: /proc/irq/*/smp_affinity ignores the values in affinity_hint if irqbalance happens to start before the driver. Expected results: /proc/irq/*/smp_affinity values should be consistent with the affinity_hint values. Additional info: The attached patch seems to fix the problem for network drivers.