kfdtest: Also detect under-reporting of available memory

Detect under-reporting of available memory by initially attempting to
allocate substantially more than reported available memory, and ensure
that the allocation fails. Continue shrinking the attempted allocation
until it succeeds, then fail the test if the successful allocation is
either too much more than or too much less than reported available.

Signed-off-by: Daniel Phillips <daniel.phillips@amd.com>
Change-Id: Ib418f0aa26e8db80590a6c5f2578da56a4b60f2b

tests/kfdtest/src/KFDMemoryTest.cpp

@@ -264,23 +264,32 @@ TEST_F(KFDMemoryTest, MemoryAlloc) {
 // Basic test for hsaKmtAllocMemory
 TEST_F(KFDMemoryTest, MemoryAllocAll) {
     TEST_START(TESTPROFILE_RUNALL)
-
     int defaultGPUNode = m_NodeInfo.HsaDefaultGPUNode();
     HsaMemFlags memFlags = {0};
     memFlags.ui32.NonPaged = 1; // sys mem vs vram
     HSAuint64 available;
     void *object = NULL;
     int shrink = 21, success = HSAKMT_STATUS_NO_MEMORY;
-
     EXPECT_SUCCESS(hsaKmtAvailableMemory(defaultGPUNode, &available));
     LOG() << "Available: " << available << " bytes" << std::endl;
+    HSAuint64 leeway = (10 << shrink), size = available + leeway;
     for (int i = 0; i < available >> shrink; i++) {
-        HSAuint64 size = available - ((HSAuint64)i << shrink);
         if (hsaKmtAllocMemory(defaultGPUNode, size, memFlags, &object) == HSAKMT_STATUS_SUCCESS) {
-            LOG() << "Allocated: " << size << " bytes" << std::endl;
             success = hsaKmtFreeMemory(object, available);
             break;
         }
+        size -= (1 << shrink);
+    }
+    if (success == HSAKMT_STATUS_SUCCESS) {
+        LOG() << "Allocated: " << size << " bytes" << std::endl;
+        if (size > available + leeway) {
+            LOG() << "Under-reported available memory!" << std::endl;
+            success = HSAKMT_STATUS_ERROR;
+        }
+        if (size < available - leeway) {
+            LOG() << "Over-reported available memory!" << std::endl;
+            success = HSAKMT_STATUS_NO_MEMORY;
+        }
     }
     EXPECT_SUCCESS(success);
     TEST_END