[compiler-rt] [scudo] Add partial chunk heuristic to retrieval algorithm. (PR #104807)

[via llvm-commits]

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@@ -336,6 +337,37 @@ TEST_F(MapAllocatorCacheTest, CacheOrder) {
     MemMap.unmap();
 }
 
+TEST_F(MapAllocatorCacheTest, PartialChunkHeuristicRetrievalTest) {
+  const scudo::uptr MaxUnusedCacheBytes = scudo::MaxUnusedCachePages * PageSize;
+  const scudo::uptr FragmentedBytes =
+      MaxUnusedCacheBytes +
+      scudo::roundDown(scudo::CachedBlock::ReleaseMemoryUpperBound, PageSize);
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ChiaHungDuan wrote:

I think that `scudo::CachedBlock::ReleaseMemoryUpperBound` should always align to `PageSize` so maybe we can remove the roundDown()

https://github.com/llvm/llvm-project/pull/104807