--- old/src/hotspot/os/windows/os_windows.cpp	2020-08-26 13:30:04.874994075 +0200
+++ new/src/hotspot/os/windows/os_windows.cpp	2020-08-26 13:30:04.698989464 +0200
@@ -2698,121 +2698,6 @@
   #define MEM_LARGE_PAGES 0x20000000
 #endif
 
-#define VirtualFreeChecked(mem, size, type)                       \
-  do {                                                            \
-    bool ret = VirtualFree(mem, size, type);                      \
-    assert(ret, "Failed to free memory: " PTR_FORMAT, p2i(mem));  \
-  } while (false)
-
-// The number of bytes is setup to match 1 pixel and 32 bits per pixel.
-static const int gdi_tiny_bitmap_width_bytes = 4;
-
-static HBITMAP gdi_create_tiny_bitmap(void* mem) {
-  // The documentation for CreateBitmap states a word-alignment requirement.
-  STATIC_ASSERT(is_aligned_(gdi_tiny_bitmap_width_bytes, sizeof(WORD)));
-
-  // Some callers use this function to test if memory crossing separate memory
-  // reservations can be used. Create a height of 2 to make sure that one pixel
-  // ends up in the first reservation and the other in the second.
-  int nHeight = 2;
-
-  assert(is_aligned(mem, gdi_tiny_bitmap_width_bytes), "Incorrect alignment");
-
-  // Width is one pixel and correlates with gdi_tiny_bitmap_width_bytes.
-  int nWidth = 1;
-
-  // Calculate bit count - will be 32.
-  UINT nBitCount = gdi_tiny_bitmap_width_bytes / nWidth * BitsPerByte;
-
-  return CreateBitmap(
-      nWidth,
-      nHeight,
-      1,         // nPlanes
-      nBitCount,
-      mem);      // lpBits
-}
-
-// It has been found that some of the GDI functions fail under these two situations:
-//  1) When used with large pages
-//  2) When mem crosses the boundary between two separate memory reservations.
-//
-// This is a small test used to see if the current GDI implementation is
-// susceptible to any of these problems.
-static bool gdi_can_use_memory(void* mem) {
-  HBITMAP bitmap = gdi_create_tiny_bitmap(mem);
-  if (bitmap != NULL) {
-    DeleteObject(bitmap);
-    return true;
-  }
-
-  // Verify that the bitmap could be created with a normal page.
-  // If this fails, the testing method above isn't reliable.
-#ifdef ASSERT
-  void* verify_mem = ::malloc(4 * 1024);
-  HBITMAP verify_bitmap = gdi_create_tiny_bitmap(verify_mem);
-  if (verify_bitmap == NULL) {
-    fatal("Couldn't create test bitmap with malloced memory");
-  } else {
-    DeleteObject(verify_bitmap);
-  }
-  ::free(verify_mem);
-#endif
-
-  return false;
-}
-
-// Test if GDI functions work when memory spans
-// two adjacent memory reservations.
-static bool gdi_can_use_split_reservation_memory() {
-  size_t granule = os::vm_allocation_granularity();
-
-  // Find virtual memory range
-  void* reserved = VirtualAlloc(NULL,
-                                granule * 2,
-                                MEM_RESERVE,
-                                PAGE_NOACCESS);
-  if (reserved == NULL) {
-    // Can't proceed with test - pessimistically report false
-    return false;
-  }
-  VirtualFreeChecked(reserved, 0, MEM_RELEASE);
-
-  void* res0 = reserved;
-  void* res1 = (char*)reserved + granule;
-
-  // Reserve and commit the first part
-  void* mem0 = VirtualAlloc(res0,
-                            granule,
-                            MEM_RESERVE|MEM_COMMIT,
-                            PAGE_READWRITE);
-  if (mem0 != res0) {
-    // Can't proceed with test - pessimistically report false
-    return false;
-  }
-
-  // Reserve and commit the second part
-  void* mem1 = VirtualAlloc(res1,
-                            granule,
-                            MEM_RESERVE|MEM_COMMIT,
-                            PAGE_READWRITE);
-  if (mem1 != res1) {
-    VirtualFreeChecked(mem0, 0, MEM_RELEASE);
-    // Can't proceed with test - pessimistically report false
-    return false;
-  }
-
-  // Set the bitmap's bits to point one "width" bytes before, so that
-  // the bitmap extends across the reservation boundary.
-  void* bitmapBits = (char*)mem1 - gdi_tiny_bitmap_width_bytes;
-
-  bool success = gdi_can_use_memory(bitmapBits);
-
-  VirtualFreeChecked(mem1, 0, MEM_RELEASE);
-  VirtualFreeChecked(mem0, 0, MEM_RELEASE);
-
-  return success;
-}
-
 // Container for NUMA node list info
 class NUMANodeListHolder {
  private:
@@ -2914,12 +2799,6 @@
     WARN("...Ignoring UseNUMAInterleaving flag.");
     return false;
   }
-
-  if (!gdi_can_use_split_reservation_memory()) {
-    WARN("Windows GDI cannot handle split reservations.");
-    WARN("...Ignoring UseNUMAInterleaving flag.");
-    return false;
-  }
 
   if (log_is_enabled(Debug, os, cpu)) {
     Log(os, cpu) log;