[SERVER-16643] extend existing THP warning to THP defrag setting Created: 23/Dec/14 Updated: 05/Sep/18 Resolved: 15/Jan/15 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Admin, Performance |
| Affects Version/s: | 2.8.0-rc3 |
| Fix Version/s: | 3.0.0-rc6 |
| Type: | Improvement | Priority: | Major - P3 |
| Reporter: | Asya Kamsky | Assignee: | Benety Goh |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Backwards Compatibility: | Fully Compatible | ||||||||||||||||||||||||||||
| Participants: | |||||||||||||||||||||||||||||
| Description |
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We currently check certain system parameters at start-up including high read-ahead and transparent huge pages. It turns out even if THP are disabled (enabled set to [never]) if defrag is "always" then it impacts mongod when Linux defrags the pages. We should extend the check and the warning to /sys/kernel/mm/transparent_hugepage/defrag |
| Comments |
| Comment by Githook User [ 15/Jan/15 ] |
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Author: {u'username': u'benety', u'name': u'Benety Goh', u'email': u'benety@mongodb.com'}Message: At startup under Linux, mongod will check the following files: /sys/kernel/mm/transparent_hugepage/enabled and produce a warning if either of these parameters are set to [always]. The recommended setting is [never] for both parameters. See: http://docs.mongodb.org/manual/administration/production-notes/#recommended-configuration |
| Comment by Daniel Pasette (Inactive) [ 23/Dec/14 ] |
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It was found that this setting has a large impact on some workloads as seen in |