Enable free lists when each dense tensor use the same amount of memory (all dimensions are bound).

2 files changed, 9 insertions, 1 deletions

diff --git a/searchlib/src/tests/attribute/tensorattribute/tensorattribute_test.cpp b/searchlib/src/tests/attribute/tensorattribute/tensorattribute_test.cpp
index 2e339a069b6..bd814b0ad32 100644
--- a/searchlib/src/tests/attribute/tensorattribute/tensorattribute_test.cpp
+++ b/searchlib/src/tests/attribute/tensorattribute/tensorattribute_test.cpp
@@ -307,6 +307,10 @@ Fixture::testSaveLoad()
 void
 Fixture::testCompaction()
 {
+    if (_useDenseTensorAttribute && _denseTensors && !_cfg.tensorType().is_abstract()) {
+        LOG(info, "Skipping compaction test for tensor '%s' which is using free-lists", _cfg.tensorType().to_spec().c_str());
+        return;
+    }
     ensureSpace(4);
     Tensor::UP emptytensor = _tensorAttr->getEmptyTensor();
     Tensor::UP emptyxytensor = createTensor({}, {"x", "y"});
diff --git a/searchlib/src/vespa/searchlib/tensor/dense_tensor_store.cpp b/searchlib/src/vespa/searchlib/tensor/dense_tensor_store.cpp
index 18c52c21206..eae0f5364b8 100644
--- a/searchlib/src/vespa/searchlib/tensor/dense_tensor_store.cpp
+++ b/searchlib/src/vespa/searchlib/tensor/dense_tensor_store.cpp
@@ -79,6 +79,10 @@ DenseTensorStore::DenseTensorStore(const ValueType &type)
     _emptyCells.resize(_tensorSizeCalc._numBoundCells, 0.0);
     _store.addType(&_bufferType);
     _store.initActiveBuffers();
+    if (_tensorSizeCalc._numUnboundDims == 0) {
+        // In this case each tensor use the same amount of memory and we can re-use previously allocated raw buffers by using free lists.
+        _store.enableFreeLists();
+    }
 }
 
 DenseTensorStore::~DenseTensorStore()
@@ -120,7 +124,7 @@ DenseTensorStore::allocRawBuffer(size_t numCells)
 {
     size_t bufSize = numCells * _tensorSizeCalc._cellSize;
     size_t alignedBufSize = alignedSize(numCells);
-    auto result = _concreteStore.rawAllocator<char>(_typeId).alloc(alignedBufSize);
+    auto result = _concreteStore.freeListRawAllocator<char>(_typeId).alloc(alignedBufSize);
     clearPadAreaAfterBuffer(result.data, bufSize, alignedBufSize, unboundDimSizesSize());
     return result;
 }