2473 bool os::release_memory_special(char* base, size_t bytes) {
2474 // Detaching the SHM segment will also delete it, see reserve_memory_special().
2475 Unimplemented();
2476 return false;
2477 }
2478
2479 size_t os::large_page_size() {
2480 return _large_page_size;
2481 }
2482
2483 bool os::can_commit_large_page_memory() {
2484 // Does not matter, we do not support huge pages.
2485 return false;
2486 }
2487
2488 bool os::can_execute_large_page_memory() {
2489 // Does not matter, we do not support huge pages.
2490 return false;
2491 }
2492
2493 // Reserve memory at an arbitrary address, only if that area is
2494 // available (and not reserved for something else).
2495 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2496 char* addr = 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
2501 // In 4K mode always use mmap.
2502 // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2503 if (os::vm_page_size() == 4*K) {
2504 return reserve_mmaped_memory(bytes, requested_addr, 0);
2505 } else {
2506 if (bytes >= Use64KPagesThreshold) {
2507 return reserve_shmated_memory(bytes, requested_addr, 0);
2508 } else {
2509 return reserve_mmaped_memory(bytes, requested_addr, 0);
2510 }
2511 }
2512
|
2473 bool os::release_memory_special(char* base, size_t bytes) {
2474 // Detaching the SHM segment will also delete it, see reserve_memory_special().
2475 Unimplemented();
2476 return false;
2477 }
2478
2479 size_t os::large_page_size() {
2480 return _large_page_size;
2481 }
2482
2483 bool os::can_commit_large_page_memory() {
2484 // Does not matter, we do not support huge pages.
2485 return false;
2486 }
2487
2488 bool os::can_execute_large_page_memory() {
2489 // Does not matter, we do not support huge pages.
2490 return false;
2491 }
2492
2493 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2494 assert(file_desc >= 0, "file_desc is not valid");
2495 char* result = NULL;
2496
2497 // Always round to os::vm_page_size(), which may be larger than 4K.
2498 bytes = align_up(bytes, os::vm_page_size());
2499 result = reserve_mmaped_memory(bytes, requested_addr, 0);
2500
2501 if (result != NULL) {
2502 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2503 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2504 }
2505 }
2506 return result;
2507 }
2508
2509 // Reserve memory at an arbitrary address, only if that area is
2510 // available (and not reserved for something else).
2511 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2512 char* addr = NULL;
2513
2514 // Always round to os::vm_page_size(), which may be larger than 4K.
2515 bytes = align_up(bytes, os::vm_page_size());
2516
2517 // In 4K mode always use mmap.
2518 // In 64K mode allocate small sizes with mmap, large ones with 64K shmatted.
2519 if (os::vm_page_size() == 4*K) {
2520 return reserve_mmaped_memory(bytes, requested_addr, 0);
2521 } else {
2522 if (bytes >= Use64KPagesThreshold) {
2523 return reserve_shmated_memory(bytes, requested_addr, 0);
2524 } else {
2525 return reserve_mmaped_memory(bytes, requested_addr, 0);
2526 }
2527 }
2528
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