Checkpoint cleanup doesn't check for the page modified information before deciding whether the page is obsolete or not. The reconciliation results get stale once the page is modified.

Treating these pages as obsolete and marking them for urgent eviction leads to unnecessary page eviction that is not required. To avoid unnecessary page eviction checkpoint cleanup check for the page modified flag before verifying the obsoleteness based on the reconciliation results.

The suggested solution doesn't fix the race condition of page modification with checkpoint cleanup marking the page for urgent eviction. This situation is rare, even if it occurred it doesn't cause any problems other than page eviction.