# HG changeset patch
# User coleenp
# Date 1240344771 14400
# Node ID c8152ae3f3396aa2bf5007ea6f82a71a2a6a45f4
# Parent  981375ca07b7f0605f92f57aad95122e8c385a4d
6830069: UseLargePages is broken on Win64
Summary: Making VirtualAlloc/VirtualProtect two calls for PAGE_EXECUTE_READWRITE doesn't work for MEM_LARGE_PAGES.
Reviewed-by: xlu, kvn, jcoomes

diff -r 981375ca07b7 -r c8152ae3f339 src/os/windows/vm/os_windows.cpp
--- a/src/os/windows/vm/os_windows.cpp	Fri Apr 17 12:22:18 2009 -0700
+++ b/src/os/windows/vm/os_windows.cpp	Tue Apr 21 16:12:51 2009 -0400
@@ -2632,6 +2632,8 @@
 
 char* os::reserve_memory_special(size_t bytes, char* addr, bool exec) {
 
+  const DWORD prot = exec ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
+
   if (UseLargePagesIndividualAllocation) {
     if (TracePageSizes && Verbose) {
        tty->print_cr("Reserving large pages individually.");
@@ -2694,13 +2696,7 @@
         p_new = (char *) VirtualAlloc(next_alloc_addr,
                                     bytes_to_rq,
                                     MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES,
-                                    PAGE_READWRITE);
-        if (p_new != NULL && exec) {
-          DWORD oldprot;
-          // Windows doc says to use VirtualProtect to get execute permissions
-          VirtualProtect(next_alloc_addr, bytes_to_rq,
-                         PAGE_EXECUTE_READWRITE, &oldprot);
-        }
+                                    prot);
       }
 
       if (p_new == NULL) {
@@ -2729,12 +2725,7 @@
   } 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_READWRITE);
-    if (res != NULL && exec) {
-      DWORD oldprot;
-      // Windows doc says to use VirtualProtect to get execute permissions
-      VirtualProtect(res, bytes, PAGE_EXECUTE_READWRITE, &oldprot);
-    }
+    char * res = (char *)VirtualAlloc(NULL, bytes, flag, prot);
     return res;
   }
 }