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src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.hpp

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rev 7696 : 8058354: SPECjvm2008-Derby -2.7% performance regression on Solaris-X64 starting with 9-b29
Summary: Allow partial use of large pages for auxiliary data structures in G1.
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*** 32,52 **** // Virtual space management helper for a virtual space with an OS page allocation // granularity. // (De-)Allocation requests are always OS page aligned by passing a page index // and multiples of pages. // The implementation gives an error when trying to commit or uncommit pages that // have already been committed or uncommitted. class G1PageBasedVirtualSpace VALUE_OBJ_CLASS_SPEC { friend class VMStructs; private: // Reserved area addresses. char* _low_boundary; char* _high_boundary; ! // The commit/uncommit granularity in bytes. ! size_t _page_size; // Bitmap used for verification of commit/uncommit operations. BitMap _committed; // Bitmap used to keep track of which pages are dirty or not for _special --- 32,57 ---- // Virtual space management helper for a virtual space with an OS page allocation // granularity. // (De-)Allocation requests are always OS page aligned by passing a page index // and multiples of pages. + // We only support reservations which base address is aligned to a given commit + // size. The length of the area managed need not commit size aligned (but OS default + // page size aligned) because some OSes cannot provide a an os_commit_size aligned + // reservation without also being size-aligned. Any tail area is committed using OS + // small pages. // The implementation gives an error when trying to commit or uncommit pages that // have already been committed or uncommitted. class G1PageBasedVirtualSpace VALUE_OBJ_CLASS_SPEC { friend class VMStructs; private: // Reserved area addresses. char* _low_boundary; char* _high_boundary; ! // The preferred commit/uncommit granularity in bytes. ! size_t _commit_size; // Bitmap used for verification of commit/uncommit operations. BitMap _committed; // Bitmap used to keep track of which pages are dirty or not for _special
*** 60,75 **** bool _special; // Indicates whether the committed space should be executable. bool _executable; // Returns the index of the page which contains the given address. uintptr_t addr_to_page_index(char* addr) const; // Returns the address of the given page index. char* page_start(uintptr_t index); ! // Returns the byte size of the given number of pages. ! size_t byte_size_for_pages(size_t num); // Returns true if the entire area is backed by committed memory. bool is_area_committed(uintptr_t start, size_t size_in_pages) const; // Returns true if the entire area is not backed by committed memory. bool is_area_uncommitted(uintptr_t start, size_t size_in_pages) const; --- 65,87 ---- bool _special; // Indicates whether the committed space should be executable. bool _executable; + // Commit the given memory range by using _commit_size pages as much as possible + // and the remainder with small sized pages. The start address must be _commit_size + // aligned. + void commit_int(char* start, char* end); + // Uncommit the given memory range. + void uncommit_int(char* start, char* end); + // Returns the index of the page which contains the given address. uintptr_t addr_to_page_index(char* addr) const; // Returns the address of the given page index. char* page_start(uintptr_t index); ! // Returns the address of the given page index ranging from 0..size_in_pages-1. ! char* page_end(uintptr_t index); // Returns true if the entire area is backed by committed memory. bool is_area_committed(uintptr_t start, size_t size_in_pages) const; // Returns true if the entire area is not backed by committed memory. bool is_area_uncommitted(uintptr_t start, size_t size_in_pages) const;
*** 83,93 **** // Uncommit the given area of pages starting at start being size_in_pages large. void uncommit(uintptr_t start, size_t size_in_pages); // Initialization G1PageBasedVirtualSpace(); ! bool initialize_with_granularity(ReservedSpace rs, size_t page_size); // Destruction ~G1PageBasedVirtualSpace(); // Amount of reserved memory. --- 95,107 ---- // Uncommit the given area of pages starting at start being size_in_pages large. void uncommit(uintptr_t start, size_t size_in_pages); // Initialization G1PageBasedVirtualSpace(); ! // Initialize the given reserved space with the given base address and actual size. ! // Prefer to commit in commit_size chunks. ! bool initialize_with_granularity(ReservedSpace rs, size_t actual_size, size_t commit_size); // Destruction ~G1PageBasedVirtualSpace(); // Amount of reserved memory.
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