2474 bool os::release_memory_special(char* base, size_t bytes) {
2475 // Detaching the SHM segment will also delete it, see reserve_memory_special().
2476 Unimplemented();
2477 return false;
2478 }
2479
2480 size_t os::large_page_size() {
2481 return _large_page_size;
2482 }
2483
2484 bool os::can_commit_large_page_memory() {
2485 // Does not matter, we do not support huge pages.
2486 return false;
2487 }
2488
2489 bool os::can_execute_large_page_memory() {
2490 // Does not matter, we do not support huge pages.
2491 return false;
2492 }
2493
2494 // Reserve memory at an arbitrary address, only if that area is
2495 // available (and not reserved for something else).
2496 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2497 char* addr = NULL;
2498
2499 // Always round to os::vm_page_size(), which may be larger than 4K.
2500 bytes = align_up(bytes, os::vm_page_size());
2501
2502 // In 4K mode always use mmap.
2503 // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2504 if (os::vm_page_size() == 4*K) {
2505 return reserve_mmaped_memory(bytes, requested_addr, 0);
2506 } else {
2507 if (bytes >= Use64KPagesThreshold) {
2508 return reserve_shmated_memory(bytes, requested_addr, 0);
2509 } else {
2510 return reserve_mmaped_memory(bytes, requested_addr, 0);
2511 }
2512 }
2513
|
2474 bool os::release_memory_special(char* base, size_t bytes) {
2475 // Detaching the SHM segment will also delete it, see reserve_memory_special().
2476 Unimplemented();
2477 return false;
2478 }
2479
2480 size_t os::large_page_size() {
2481 return _large_page_size;
2482 }
2483
2484 bool os::can_commit_large_page_memory() {
2485 // Does not matter, we do not support huge pages.
2486 return false;
2487 }
2488
2489 bool os::can_execute_large_page_memory() {
2490 // Does not matter, we do not support huge pages.
2491 return false;
2492 }
2493
2494 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2495 assert(file_desc >= 0, "file_desc is not valid");
2496 char* result = NULL;
2497
2498 // Always round to os::vm_page_size(), which may be larger than 4K.
2499 bytes = align_up(bytes, os::vm_page_size());
2500 result = reserve_mmaped_memory(bytes, requested_addr, 0);
2501
2502 if (result != NULL) {
2503 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2504 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2505 }
2506 }
2507 return result;
2508 }
2509
2510 // Reserve memory at an arbitrary address, only if that area is
2511 // available (and not reserved for something else).
2512 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2513 char* addr = NULL;
2514
2515 // Always round to os::vm_page_size(), which may be larger than 4K.
2516 bytes = align_up(bytes, os::vm_page_size());
2517
2518 // In 4K mode always use mmap.
2519 // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2520 if (os::vm_page_size() == 4*K) {
2521 return reserve_mmaped_memory(bytes, requested_addr, 0);
2522 } else {
2523 if (bytes >= Use64KPagesThreshold) {
2524 return reserve_shmated_memory(bytes, requested_addr, 0);
2525 } else {
2526 return reserve_mmaped_memory(bytes, requested_addr, 0);
2527 }
2528 }
2529
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