Fix Partially Filled Nursery Triggering Collection #417
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marron-at-work
approved these changes
Nov 19, 2025
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This fixes a bit of an oversight I had with triggering collections. As the allocator may be reusing pages with old objects hanging around, it is possible for pages with up to 60% utilization being grabbed for allocations. This means (with my previous approach) we technically could trigger a collection with only 40% of the nursery full.
So, instead of just incrementing a counter when we need a new allocation page, we now determine how much of the
alloc_pagewas just used for allocation, then determine whether we need to collect using this approximate usage.