🌱 Priorityqueue: Use separate b-trees for ready and non-ready items#3416
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k8s-ci-robot merged 1 commit intokubernetes-sigs:mainfrom Jan 14, 2026
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🌱 Priorityqueue: Use separate b-trees for ready and non-ready items#3416k8s-ci-robot merged 1 commit intokubernetes-sigs:mainfrom
k8s-ci-robot merged 1 commit intokubernetes-sigs:mainfrom
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This change refactors the priorityqueue to use distinct b-trees for ready and non-ready items. This simplifies the code, because the two of them effectively have different sorting requirements. We made this work using one b-tree sorted by priority first and readyAt second and then iterating through all priorities high to low until we find a ready item. While correct, this is difficult to reason about. The other issue is that currently, there is no explicit transition step from non-ready to ready. As a result, we always had to iterate over all items in case one got ready to then update metrics. With this change, we instead have an explicit event when an item gets ready and we can then update metrics for just this item and do not have to iterate over everything.
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Thank you very much!! /lgtm |
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[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: alvaroaleman, sbueringer The full list of commands accepted by this bot can be found here. The pull request process is described here DetailsNeeds approval from an approver in each of these files:
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This change refactors the priorityqueue to use distinct b-trees for ready and non-ready items. This simplifies the code, because the two of them effectively have different sorting requirements. We made this work using one b-tree sorted by priority first and readyAt second and then iterating through all priorities high to low until we find a ready item. While correct, this is difficult to reason about.
The other issue is that currently, there is no explicit transition step from non-ready to ready. As a result, we always had to iterate over all items in case one got ready to then update metrics. With this change, we instead have an explicit event when an item gets ready and we can then update metrics for just this item and do not have to iterate over everything.
This change also makes it possible to optimize some of the details further, for example the fifo arguably should be based on when items became ready for items that were added with a non-nil after rather than when they were added. Implementing this using the one tree would be extremely difficult at best.
cc @zach593 I think this should also address the perf issues you mention in karmada-io/karmada#7072
/assign @sbueringer