8016825: Large pages for the heap broken on Windows for compressed oops
Summary: Correctly pass the requested base address for the heap to the OS function to reserve memory.
Reviewed-by: brutisso, stefank
--- a/hotspot/src/os/windows/vm/os_windows.cpp Mon Aug 12 17:37:02 2013 +0200
+++ b/hotspot/src/os/windows/vm/os_windows.cpp Wed Sep 11 10:14:32 2013 +0200
@@ -3189,9 +3189,12 @@
return p_buf;
} else {
+ if (TracePageSizes && Verbose) {
+ tty->print_cr("Reserving large pages in a single large chunk.");
+ }
// normal policy just allocate it all at once
DWORD flag = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
- char * res = (char *)VirtualAlloc(NULL, bytes, flag, prot);
+ char * res = (char *)VirtualAlloc(addr, bytes, flag, prot);
if (res != NULL) {
address pc = CALLER_PC;
MemTracker::record_virtual_memory_reserve_and_commit((address)res, bytes, mtNone, pc);
@@ -5714,7 +5717,66 @@
#endif
#ifndef PRODUCT
+
+// test the code path in reserve_memory_special() that tries to allocate memory in a single
+// contiguous memory block at a particular address.
+// The test first tries to find a good approximate address to allocate at by using the same
+// method to allocate some memory at any address. The test then tries to allocate memory in
+// the vicinity (not directly after it to avoid possible by-chance use of that location)
+// This is of course only some dodgy assumption, there is no guarantee that the vicinity of
+// the previously allocated memory is available for allocation. The only actual failure
+// that is reported is when the test tries to allocate at a particular location but gets a
+// different valid one. A NULL return value at this point is not considered an error but may
+// be legitimate.
+// If -XX:+VerboseInternalVMTests is enabled, print some explanatory messages.
void TestReserveMemorySpecial_test() {
- // No tests available for this platform
-}
-#endif
+ if (!UseLargePages) {
+ if (VerboseInternalVMTests) {
+ gclog_or_tty->print("Skipping test because large pages are disabled");
+ }
+ return;
+ }
+ // save current value of globals
+ bool old_use_large_pages_individual_allocation = UseLargePagesIndividualAllocation;
+ bool old_use_numa_interleaving = UseNUMAInterleaving;
+
+ // set globals to make sure we hit the correct code path
+ UseLargePagesIndividualAllocation = UseNUMAInterleaving = false;
+
+ // do an allocation at an address selected by the OS to get a good one.
+ const size_t large_allocation_size = os::large_page_size() * 4;
+ char* result = os::reserve_memory_special(large_allocation_size, os::large_page_size(), NULL, false);
+ if (result == NULL) {
+ if (VerboseInternalVMTests) {
+ gclog_or_tty->print("Failed to allocate control block with size "SIZE_FORMAT". Skipping remainder of test.",
+ large_allocation_size);
+ }
+ } else {
+ os::release_memory_special(result, large_allocation_size);
+
+ // allocate another page within the recently allocated memory area which seems to be a good location. At least
+ // we managed to get it once.
+ const size_t expected_allocation_size = os::large_page_size();
+ char* expected_location = result + os::large_page_size();
+ char* actual_location = os::reserve_memory_special(expected_allocation_size, os::large_page_size(), expected_location, false);
+ if (actual_location == NULL) {
+ if (VerboseInternalVMTests) {
+ gclog_or_tty->print("Failed to allocate any memory at "PTR_FORMAT" size "SIZE_FORMAT". Skipping remainder of test.",
+ expected_location, large_allocation_size);
+ }
+ } else {
+ // release memory
+ os::release_memory_special(actual_location, expected_allocation_size);
+ // only now check, after releasing any memory to avoid any leaks.
+ assert(actual_location == expected_location,
+ err_msg("Failed to allocate memory at requested location "PTR_FORMAT" of size "SIZE_FORMAT", is "PTR_FORMAT" instead",
+ expected_location, expected_allocation_size, actual_location));
+ }
+ }
+
+ // restore globals
+ UseLargePagesIndividualAllocation = old_use_large_pages_individual_allocation;
+ UseNUMAInterleaving = old_use_numa_interleaving;
+}
+#endif // PRODUCT
+