diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c
index 2fe36c7505b..693c68c3a81 100644
--- a/src/backend/utils/mmgr/aset.c
+++ b/src/backend/utils/mmgr/aset.c
@@ -166,6 +166,7 @@ typedef struct AllocSetContext
 	uint32		maxBlockSize;	/* maximum block size */
 	uint32		nextBlockSize;	/* next block size to allocate */
 	uint32		allocChunkLimit;	/* effective chunk size limit */
+	uint32		expectedChunkLimit;	/* debug only: limit for current maxBlockSize */
 	/* freelist this context could be put in, or -1 if not a candidate: */
 	int			freeListIndex;	/* index in context_freelists[], or -1 */
 } AllocSetContext;
@@ -412,6 +413,20 @@ AllocSetContextCreateInternal(MemoryContext parent,
 			freelist->first_free = (AllocSet) set->header.nextchild;
 			freelist->num_free--;
 
+			if (set->maxBlockSize != maxBlockSize)
+			{
+				Size		expectedChunkLimit = ALLOC_CHUNK_LIMIT;
+
+				while (expectedChunkLimit + ALLOC_CHUNKHDRSZ >
+					   (maxBlockSize - ALLOC_BLOCKHDRSZ) / ALLOC_CHUNK_FRACTION)
+					expectedChunkLimit >>= 1;
+				set->expectedChunkLimit = expectedChunkLimit;
+
+				elog(LOG, "EVAN: recycling AllocSet context \"%s\": maxBlockSize %zu -> %zu, allocChunkLimit retained %zu, expected %zu",
+					 name, (Size) set->maxBlockSize, maxBlockSize,
+					 (Size) set->allocChunkLimit, expectedChunkLimit);
+			}
+
 			/* Update its maxBlockSize; everything else should be OK */
 			set->maxBlockSize = maxBlockSize;
 
@@ -517,6 +532,7 @@ AllocSetContextCreateInternal(MemoryContext parent,
 	while ((Size) (set->allocChunkLimit + ALLOC_CHUNKHDRSZ) >
 		   (Size) ((maxBlockSize - ALLOC_BLOCKHDRSZ) / ALLOC_CHUNK_FRACTION))
 		set->allocChunkLimit >>= 1;
+	set->expectedChunkLimit = set->allocChunkLimit;
 
 	/* Finally, do the type-independent part of context creation */
 	MemoryContextCreate((MemoryContext) set,
@@ -1028,7 +1044,19 @@ AllocSetAlloc(MemoryContext context, Size size, int flags)
 	 * AllocSetAllocLarge().
 	 */
 	if (size > set->allocChunkLimit)
+	{
+		if (size <= set->expectedChunkLimit)
+			elog(LOG, "EVAN: AllocSet context \"%s\": allocation size %zu wrongly takes malloc path; allocChunkLimit retained %zu, expected %zu",
+				 set->header.name, size, (Size) set->allocChunkLimit,
+				 (Size) set->expectedChunkLimit);
+
 		return AllocSetAllocLarge(context, size, flags);
+	}
+
+	if (size > set->expectedChunkLimit)
+		elog(LOG, "EVAN: AllocSet context \"%s\": allocation size %zu wrongly takes pooled chunk path; allocChunkLimit retained %zu, expected %zu",
+			 set->header.name, size, (Size) set->allocChunkLimit,
+			 (Size) set->expectedChunkLimit);
 
 	/*
 	 * Request is small enough to be treated as a chunk.  Look in the