[LU-11199] mdsrate open() performance degradation Created: 02/Aug/18 Updated: 13/Oct/18 Resolved: 13/Oct/18 |
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| Status: | Resolved |
| Project: | Lustre |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | Lustre 2.12.0 |
| Type: | Bug | Priority: | Major |
| Reporter: | Patrick Farrell (Inactive) | Assignee: | Patrick Farrell (Inactive) |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Issue Links: |
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| Severity: | 3 | ||||||||||||||||
| Rank (Obsolete): | 9223372036854775807 | ||||||||||||||||
| Description |
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A change in https://review.whamcloud.com/#/c/30246/ ( introduced a major regression in open() performance in at least an mdsrate open() benchmark: On a real system, this mdsrate open benchmark drops from 35K opens/second to around 11K. On a much smaller VM, I see a drop from 8K opens/second to 4K with this benchmark. The specific change is no longer attempting to grant the LOOKUP lock on opens. Oleg has a patch in flight which reverses this change, but also includes a number of other attempted optimizations: Andreas suggested I push the simpler patch to revert, with the idea that that patch can land quickly and Oleg's further optimizations can be considered separately. |
| Comments |
| Comment by Gerrit Updater [ 02/Aug/18 ] |
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Patrick Farrell (paf@cray.com) uploaded a new patch: https://review.whamcloud.com/32929 |
| Comment by Gerrit Updater [ 12/Oct/18 ] |
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Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/32929/ |
| Comment by Peter Jones [ 13/Oct/18 ] |
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Landed for 2.12 |