Add env key to disable 2MB suballocation.

Change-Id: Icca3041c3578aa180a656c01aae62f2ad6e8b583


[ROCm/ROCR-Runtime commit: 4275661682]

projects/rocr-runtime/runtime/hsa-runtime/core/runtime/amd_memory_region.cpp

@@ -171,7 +171,8 @@ hsa_status_t MemoryRegion::Allocate(size_t size, AllocateFlags alloc_flags,
       (alloc_flags & AllocateDoubleMap ? 1 : 0);
 
   // Only allow using the suballocator for ordinary VRAM.
-  bool useSubAlloc = IsLocalMemory();
+  bool useSubAlloc = !core::Runtime::runtime_singleton_->flag().disable_fragment_alloc();
+  useSubAlloc &= IsLocalMemory();
   useSubAlloc &= (alloc_flags == AllocateRestrict);
   useSubAlloc &= (size <= fragment_allocator_.max_alloc());
   if (useSubAlloc) {

projects/rocr-runtime/runtime/hsa-runtime/core/util/flag.h

@@ -88,6 +88,9 @@ class Flag {
 
     var = os::GetEnvVar("HSA_TOOLS_REPORT_LOAD_FAILURE");
     report_tool_load_failures_ = (var == "0") ? false : true;
+
+    var = os::GetEnvVar("HSA_DISABLE_FRAGMENT_ALLOCATOR");
+    disable_fragment_alloc_ = (var == "1") ? true : false;
   }
 
   bool check_flat_scratch() const { return check_flat_scratch_; }
@@ -104,14 +107,16 @@ class Flag {
 
   bool sdma_wait_idle() const { return sdma_wait_idle_; }
 
+  bool report_tool_load_failures() const { return report_tool_load_failures_; }
+
+  bool disable_fragment_alloc() const { return disable_fragment_alloc_; }
+
   uint32_t max_queues() const { return max_queues_; }
 
   size_t scratch_mem_size() const { return scratch_mem_size_; }
 
   std::string tools_lib_names() const { return tools_lib_names_; }
 
-  bool report_tool_load_failures() const { return report_tool_load_failures_; }
-
  private:
   bool check_flat_scratch_;
   bool enable_vm_fault_message_;
@@ -121,6 +126,7 @@ class Flag {
   bool sdma_wait_idle_;
   bool enable_queue_fault_message_;
   bool report_tool_load_failures_;
+  bool disable_fragment_alloc_;
 
   uint32_t max_queues_;