diff options
Diffstat (limited to 'src/share/vm/runtime/os.hpp')
| -rw-r--r-- | src/share/vm/runtime/os.hpp | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/src/share/vm/runtime/os.hpp b/src/share/vm/runtime/os.hpp index c1e9d45b7..944ec6431 100644 --- a/src/share/vm/runtime/os.hpp +++ b/src/share/vm/runtime/os.hpp @@ -149,6 +149,7 @@ class os: AllStatic { static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint); static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint); + static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned); public: static void init(void); // Called before command line parsing @@ -159,7 +160,6 @@ class os: AllStatic { static void init_globals(void) { // Called from init_globals() in init.cpp init_globals_ext(); } - static void init_3(void); // Called at the end of vm init // File names are case-insensitive on windows only // Override me as needed @@ -266,19 +266,16 @@ class os: AllStatic { // Return the default page size. static int vm_page_size(); - // Return the page size to use for a region of memory. The min_pages argument - // is a hint intended to limit fragmentation; it says the returned page size - // should be <= region_max_size / min_pages. Because min_pages is a hint, - // this routine may return a size larger than region_max_size / min_pages. - // - // The current implementation ignores min_pages if a larger page size is an - // exact multiple of both region_min_size and region_max_size. This allows - // larger pages to be used when doing so would not cause fragmentation; in - // particular, a single page can be used when region_min_size == - // region_max_size == a supported page size. - static size_t page_size_for_region(size_t region_min_size, - size_t region_max_size, - uint min_pages); + // Returns the page size to use for a region of memory. + // region_size / min_pages will always be greater than or equal to the + // returned value. The returned value will divide region_size. + static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages); + + // Returns the page size to use for a region of memory. + // region_size / min_pages will always be greater than or equal to the + // returned value. The returned value might not divide region_size. + static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages); + // Return the largest page size that can be used static size_t max_page_size() { // The _page_sizes array is sorted in descending order. @@ -320,6 +317,12 @@ class os: AllStatic { static bool uncommit_memory(char* addr, size_t bytes); static bool release_memory(char* addr, size_t bytes); + // Touch memory pages that cover the memory range from start to end (exclusive) + // to make the OS back the memory range with actual memory. + // Current implementation may not touch the last page if unaligned addresses + // are passed. + static void pretouch_memory(char* start, char* end); + enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX }; static bool protect_memory(char* addr, size_t bytes, ProtType prot, bool is_committed = true); |