Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: src/share/vm/runtime/os.cpp
src/share/vm/runtime/os.cpp
- changeset 7778
- c2ce24504334
- parent 7777
- 340ca8812af9
- child 7780
- 5788dbd1f2d6
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| 7777:340ca8812af9 | 7778:c2ce24504334 |
|---|---|
| 1313 // The very lower end of the stack | 1313 // The very lower end of the stack |
| 1314 address stack_limit = thread->stack_base() - thread->stack_size(); | 1314 address stack_limit = thread->stack_base() - thread->stack_size(); |
| 1315 return (sp > (stack_limit + reserved_area)); | 1315 return (sp > (stack_limit + reserved_area)); |
| 1316 } | 1316 } |
| 1317 | 1317 |
| 1318 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size, | 1318 size_t os::page_size_for_region(size_t region_size, size_t min_pages) { |
| 1319 uint min_pages) | |
| 1320 { | |
| 1321 assert(min_pages > 0, "sanity"); | 1319 assert(min_pages > 0, "sanity"); |
| 1322 if (UseLargePages) { | 1320 if (UseLargePages) { |
| 1323 const size_t max_page_size = region_max_size / min_pages; | 1321 const size_t max_page_size = region_size / min_pages; |
| 1324 | 1322 |
| 1325 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) { | 1323 for (size_t i = 0; _page_sizes[i] != 0; ++i) { |
| 1326 const size_t sz = _page_sizes[i]; | 1324 const size_t page_size = _page_sizes[i]; |
| 1327 const size_t mask = sz - 1; | 1325 if (page_size <= max_page_size && is_size_aligned(region_size, page_size)) { |
| 1328 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) { | 1326 return page_size; |
| 1329 // The largest page size with no fragmentation. | |
| 1330 return sz; | |
| 1331 } | |
| 1332 | |
| 1333 if (sz <= max_page_size) { | |
| 1334 // The largest page size that satisfies the min_pages requirement. | |
| 1335 return sz; | |
| 1336 } | 1327 } |
| 1337 } | 1328 } |
| 1338 } | 1329 } |
| 1339 | 1330 |
| 1340 return vm_page_size(); | 1331 return vm_page_size(); |
| 1572 return to; | 1563 return to; |
| 1573 } | 1564 } |
| 1574 return result; | 1565 return result; |
| 1575 } | 1566 } |
| 1576 #endif | 1567 #endif |
| 1568 | |
| 1569 /////////////// Unit tests /////////////// | |
| 1570 | |
| 1571 #ifndef PRODUCT | |
| 1572 | |
| 1573 #define assert_eq(a,b) assert(a == b, err_msg(SIZE_FORMAT " != " SIZE_FORMAT, a, b)) | |
| 1574 | |
| 1575 class TestOS : AllStatic { | |
| 1576 static size_t small_page_size() { | |
| 1577 return os::vm_page_size(); | |
| 1578 } | |
| 1579 | |
| 1580 static size_t large_page_size() { | |
| 1581 const size_t large_page_size_example = 4 * M; | |
| 1582 return os::page_size_for_region(large_page_size_example, 1); | |
| 1583 } | |
| 1584 | |
| 1585 static void test_page_size_for_region() { | |
| 1586 if (UseLargePages) { | |
| 1587 const size_t small_page = small_page_size(); | |
| 1588 const size_t large_page = large_page_size(); | |
| 1589 | |
| 1590 if (large_page > small_page) { | |
| 1591 size_t num_small_pages_in_large = large_page / small_page; | |
| 1592 size_t page = os::page_size_for_region(large_page, num_small_pages_in_large); | |
| 1593 | |
| 1594 assert_eq(page, small_page); | |
| 1595 } | |
| 1596 } | |
| 1597 } | |
| 1598 | |
| 1599 static void test_page_size_for_region_alignment() { | |
| 1600 if (UseLargePages) { | |
| 1601 const size_t small_page = small_page_size(); | |
| 1602 const size_t large_page = large_page_size(); | |
| 1603 if (large_page > small_page) { | |
| 1604 const size_t unaligned_region = large_page + 17; | |
| 1605 size_t page = os::page_size_for_region(unaligned_region, 1); | |
| 1606 assert_eq(page, small_page); | |
| 1607 | |
| 1608 const size_t num_pages = 5; | |
| 1609 const size_t aligned_region = large_page * num_pages; | |
| 1610 page = os::page_size_for_region(aligned_region, num_pages); | |
| 1611 assert_eq(page, large_page); | |
| 1612 } | |
| 1613 } | |
| 1614 } | |
| 1615 | |
| 1616 public: | |
| 1617 static void run_tests() { | |
| 1618 test_page_size_for_region(); | |
| 1619 test_page_size_for_region_alignment(); | |
| 1620 } | |
| 1621 }; | |
| 1622 | |
| 1623 void TestOS_test() { | |
| 1624 TestOS::run_tests(); | |
| 1625 } | |
| 1626 | |
| 1627 #endif // PRODUCT |
