[SERVER-54685] wrong definition of MONGO_YIELD_CORE_FOR_SMT for arm64 Created: 21/Feb/21 Updated: 29/Oct/23 Resolved: 24/Feb/21 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | 4.9.0, 4.2.13, 4.4.5 |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Tsahi Zidenberg | Assignee: | Andrew Morrow (Inactive) |
| Resolution: | Fixed | 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 | ||||||||||||
| Operating System: | ALL | ||||||||||||
| Backport Requested: |
v4.4, v4.2
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| Sprint: | Dev Platform 2021-03-08 | ||||||||||||
| Participants: | |||||||||||||
| Description |
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MONGO_YIELD_CORE_FOR_SMT is defined as the yield instuction, but yield is just a nop in arm64. Using an "isb" instruction is a better implementation. The Instruction Synchronization Barrier will create a very small delay without taking other CPU resources, which is required while spinning on a spinlock. |
| Comments |
| Comment by Githook User [ 26/Feb/21 ] |
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Author: {'name': 'Andrew Morrow', 'email': 'acm@mongodb.com', 'username': 'acmorrow'}Message: (cherry picked from commit 6979525674af67405984c58585766dd4d0c3f2a8) |
| Comment by Githook User [ 26/Feb/21 ] |
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Author: {'name': 'Andrew Morrow', 'email': 'acm@mongodb.com', 'username': 'acmorrow'}Message: (cherry picked from commit 6979525674af67405984c58585766dd4d0c3f2a8) |
| Comment by Githook User [ 24/Feb/21 ] |
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Author: {'name': 'Andrew Morrow', 'email': 'acm@mongodb.com', 'username': 'acmorrow'}Message: |
| Comment by Andrew Morrow (Inactive) [ 21/Feb/21 ] |
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tsahee@amazon.com - No problem, we will handle it on our side then. |
| Comment by Tsahi Zidenberg [ 21/Feb/21 ] |
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@acm I am not able to send PRs to mongodb. Please handle it on your side, and let me know if any questions come up. Thank you! |
| Comment by Andrew Morrow (Inactive) [ 21/Feb/21 ] |
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tsahee@amazon.com - Thanks for filing the ticket. I see that a very similar change was made in the WT sources in |