6660681: Incrementally reserve pages on win server 2003 for better large page affinity

For windows server 2003 added option to reserve large pages individually.

Reviewed-by: alanb, jcoomes, tonyp, apetrusenko

hotspot/src/os/windows/vm/os_windows.cpp

@@ -2593,9 +2593,104 @@ bool os::can_execute_large_page_memory() {
 }
 
 char* os::reserve_memory_special(size_t bytes) {
-  DWORD flag = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
-  char * res = (char *)VirtualAlloc(NULL, bytes, flag, PAGE_EXECUTE_READWRITE);
-  return res;
+
+  if (UseLargePagesIndividualAllocation) {
+    if (TracePageSizes && Verbose) {
+       tty->print_cr("Reserving large pages individually.");
+    }
+    char * p_buf;
+    // first reserve enough address space in advance since we want to be
+    // able to break a single contiguous virtual address range into multiple
+    // large page commits but WS2003 does not allow reserving large page space
+    // so we just use 4K pages for reserve, this gives us a legal contiguous
+    // address space. then we will deallocate that reservation, and re alloc
+    // using large pages
+    const size_t size_of_reserve = bytes + _large_page_size;
+    if (bytes > size_of_reserve) {
+      // Overflowed.
+      warning("Individually allocated large pages failed, "
+        "use -XX:-UseLargePagesIndividualAllocation to turn off");
+      return NULL;
+    }
+    p_buf = (char *) VirtualAlloc(NULL,
+                                 size_of_reserve,  // size of Reserve
+                                 MEM_RESERVE,
+                                 PAGE_EXECUTE_READWRITE);
+    // If reservation failed, return NULL
+    if (p_buf == NULL) return NULL;
+
+    release_memory(p_buf, bytes + _large_page_size);
+    // round up to page boundary.  If the size_of_reserve did not
+    // overflow and the reservation did not fail, this align up
+    // should not overflow.
+    p_buf = (char *) align_size_up((size_t)p_buf, _large_page_size);
+
+    // now go through and allocate one page at a time until all bytes are
+    // allocated
+    size_t  bytes_remaining = align_size_up(bytes, _large_page_size);
+    // An overflow of align_size_up() would have been caught above
+    // in the calculation of size_of_reserve.
+    char * next_alloc_addr = p_buf;
+
+#ifdef ASSERT
+    // Variable for the failure injection
+    long ran_num = os::random();
+    size_t fail_after = ran_num % bytes;
+#endif
+
+    while (bytes_remaining) {
+      size_t bytes_to_rq = MIN2(bytes_remaining, _large_page_size);
+      // Note allocate and commit
+      char * p_new;
+
+#ifdef ASSERT
+      bool inject_error = LargePagesIndividualAllocationInjectError &&
+          (bytes_remaining <= fail_after);
+#else
+      const bool inject_error = false;
+#endif
+
+      if (inject_error) {
+        p_new = NULL;
+      } else {
+        p_new = (char *) VirtualAlloc(next_alloc_addr,
+                                    bytes_to_rq,
+                                    MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES,
+                                    PAGE_EXECUTE_READWRITE);
+      }
+
+      if (p_new == NULL) {
+        // Free any allocated pages
+        if (next_alloc_addr > p_buf) {
+          // Some memory was committed so release it.
+          size_t bytes_to_release = bytes - bytes_remaining;
+          release_memory(p_buf, bytes_to_release);
+        }
+#ifdef ASSERT
+        if (UseLargePagesIndividualAllocation &&
+            LargePagesIndividualAllocationInjectError) {
+          if (TracePageSizes && Verbose) {
+             tty->print_cr("Reserving large pages individually failed.");
+          }
+        }
+#endif
+        return NULL;
+      }
+      bytes_remaining -= bytes_to_rq;
+      next_alloc_addr += bytes_to_rq;
+    }
+
+    return p_buf;
+
+  } else {
+    // normal policy just allocate it all at once
+    DWORD flag = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
+    char * res = (char *)VirtualAlloc(NULL,
+                                      bytes,
+                                      flag,
+                                      PAGE_EXECUTE_READWRITE);
+    return res;
+  }
 }
 
 bool os::release_memory_special(char* base, size_t bytes) {
@@ -2983,6 +3078,7 @@ size_t os::win32::_default_stack_size = 0;
 volatile intx os::win32::_os_thread_count    = 0;
 
 bool   os::win32::_is_nt              = false;
+bool   os::win32::_is_windows_2003    = false;
 
 
 void os::win32::initialize_system_info() {
@@ -3005,7 +3101,15 @@ void os::win32::initialize_system_info() {
   GetVersionEx(&oi);
   switch(oi.dwPlatformId) {
     case VER_PLATFORM_WIN32_WINDOWS: _is_nt = false; break;
-    case VER_PLATFORM_WIN32_NT:      _is_nt = true;  break;
+    case VER_PLATFORM_WIN32_NT:
+      _is_nt = true;
+      {
+        int os_vers = oi.dwMajorVersion * 1000 + oi.dwMinorVersion;
+        if (os_vers == 5002) {
+          _is_windows_2003 = true;
+        }
+      }
+      break;
     default: fatal("Unknown platform");
   }
 
@@ -3103,9 +3207,13 @@ void os::init(void) {
     NoYieldsInMicrolock = true;
   }
 #endif
+  // This may be overridden later when argument processing is done.
+  FLAG_SET_ERGO(bool, UseLargePagesIndividualAllocation,
+    os::win32::is_windows_2003());
+
   // Initialize main_process and main_thread
   main_process = GetCurrentProcess();  // Remember main_process is a pseudo handle
-  if (!DuplicateHandle(main_process, GetCurrentThread(), main_process,
+ if (!DuplicateHandle(main_process, GetCurrentThread(), main_process,
                        &main_thread, THREAD_ALL_ACCESS, false, 0)) {
     fatal("DuplicateHandle failed\n");
   }