fix overallocation for memory-mapped workspaces

Signed-off-by: raver119 <raver119@gmail.com>

nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/api/memory/abstracts/Nd4jWorkspace.java

@@ -297,9 +297,8 @@ public abstract class Nd4jWorkspace implements MemoryWorkspace {
     }
 
     protected void init() {
-        //  we want params validation here
+        // we don't want overallocation in case of MMAP
-
+        if (currentSize.get() > 0 && workspaceConfiguration.getPolicyLocation()  != LocationPolicy.MMAP) {
-        if (currentSize.get() > 0) {
             if (!isOver.get()) {
                 if (workspaceConfiguration.getPolicyAllocation() == AllocationPolicy.OVERALLOCATE
                                 && workspaceConfiguration.getOverallocationLimit() > 0) {

nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/linalg/cpu/nativecpu/workspace/CpuWorkspace.java

@@ -92,11 +92,9 @@ public class CpuWorkspace extends Nd4jWorkspace implements Deallocatable {
             if (currentSize.get() > 0) {
                 isInit.set(true);
 
-
+                if (isDebug.get())
-                //if (isDebug.get())
                     log.info("Allocating [{}] workspace of {} bytes...", id, currentSize.get());
 
-
                 workspace.setHostPointer(new PagedPointer(memoryManager.allocate(currentSize.get() + SAFETY_OFFSET, MemoryKind.HOST, true)));
                 AllocationsTracker.getInstance().markAllocated(AllocationKind.WORKSPACE, 0, currentSize.get() + SAFETY_OFFSET);
             }

nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/workspace/SpecialWorkspaceTests.java

@@ -26,16 +26,14 @@ import org.nd4j.linalg.BaseNd4jTest;
 import org.nd4j.linalg.api.buffer.DataType;
 import org.nd4j.linalg.api.memory.MemoryWorkspace;
 import org.nd4j.linalg.api.memory.conf.WorkspaceConfiguration;
-import org.nd4j.linalg.api.memory.enums.AllocationPolicy;
+import org.nd4j.linalg.api.memory.enums.*;
-import org.nd4j.linalg.api.memory.enums.LearningPolicy;
-import org.nd4j.linalg.api.memory.enums.ResetPolicy;
-import org.nd4j.linalg.api.memory.enums.SpillPolicy;
 import org.nd4j.linalg.api.ndarray.INDArray;
 import org.nd4j.linalg.api.ops.DynamicCustomOp;
 import org.nd4j.linalg.factory.Nd4j;
 import org.nd4j.linalg.factory.Nd4jBackend;
 import org.nd4j.linalg.api.memory.abstracts.Nd4jWorkspace;
 
+import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.Arrays;
 
@@ -335,6 +333,27 @@ public class SpecialWorkspaceTests extends BaseNd4jTest {
 
         assertEquals(exp, res);
     }
+
+    @Test
+    public void testMmapedWorkspaceLimits_1() throws Exception {
+        val tmpFile = Files.createTempFile("some", "file");
+        val mmap = WorkspaceConfiguration.builder()
+                .initialSize(200 * 1024L * 1024L) // 200mbs
+                .tempFilePath(tmpFile.toAbsolutePath().toString())
+                .policyLocation(LocationPolicy.MMAP)
+                .build();
+
+        try (val ws = Nd4j.getWorkspaceManager().getAndActivateWorkspace(mmap, "M2")) {
+            int twoHundredMbsOfFloats = 52_428_800; // 200mbs % 4
+            val addMoreFloats = true;
+            if (addMoreFloats) {
+                twoHundredMbsOfFloats += 1_000;
+            }
+
+            val x = Nd4j.rand(DataType.FLOAT, twoHundredMbsOfFloats);
+        }
+    }
+
     @Override
     public char ordering() {
         return 'c';