| Summary: | rt: fix idle_balance iterating over all CPUs if a runnable task shows up partway through | ||||||||||
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| Product: | Red Hat Enterprise Linux 7 | Reporter: | Clark Williams <williams> | ||||||||
| Component: | kernel-rt | Assignee: | Steven Rostedt <srostedt> | ||||||||
| kernel-rt sub component: | Process management | QA Contact: | Jiri Kastner <jkastner> | ||||||||
| Status: | CLOSED ERRATA | Docs Contact: | |||||||||
| Severity: | medium | ||||||||||
| Priority: | medium | CC: | bhu, bperkins, lgoncalv, riel, srostedt, williams | ||||||||
| Version: | 7.3 | ||||||||||
| Target Milestone: | rc | ||||||||||
| Target Release: | --- | ||||||||||
| Hardware: | x86_64 | ||||||||||
| OS: | Linux | ||||||||||
| Whiteboard: | |||||||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||||||
| Doc Text: | Story Points: | --- | |||||||||
| Clone Of: | Environment: | ||||||||||
| Last Closed: | 2016-11-03 19:48:49 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: | |||||||||
| Bug Depends On: | |||||||||||
| Bug Blocks: | 1274397 | ||||||||||
| Attachments: |
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Description
Clark Williams
2016-04-28 19:40:23 UTC
There are a few separate issues here: 1) idle_balance is currently called with irqs disabled, Steven Rostedt has a patch to fix that 2) idle_balance continues to iterate over all CPUs even if a runnable task shows up during balancing, I have a patch to fix that We need both of these fixes together to get the system to behave better. Created attachment 1152052 [details]
break out of idle_balance if an RT task is ready to run
Created attachment 1152053 [details]
Enable irqs in idle_balance() routine
Created attachment 1152054 [details]
Move call to idle_balance to post-schedule
The above three patches have been applied to a scratch build based on kernel-rt-3.10.0-382.rt56.263.el7 and are under testing now Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHSA-2016-2584.html |