Use small page size/flags for Sparse Virtual Memory #7164
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@amicic please review. |
amicic
approved these changes
Oct 30, 2023
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@babsingh Would you please help to merge this change?
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https://github.com/eclipse/omr/blob/master/CONTRIBUTING.md#commit-guidelines The title (first line) shouldn't end with a period: Otherwise, the changes LGTM. |
Currently Sparse Virtual Memory uses page size Object Heap is allocated with. We want to use small pages for Sparse Heap always regardless. Also Sparse Virtual Memory uses page flags "requested" for Object Heap. This is the bug. Page flags should be paired with the page size. Please note, that current MM_SparseVirtualMemory implementation can use double mapping instead of off-heap. This is an experimental feature never used in the code and not planned to be used. This feature uses hidden assumption that memory page size/flags should be the same for Object and Sparse heaps. This PR can break it potentially in the case memory page settings in the Object Heap and Sparse heap are different. We are going to be aware about this if we need another round of experimental testing with double mapping support. Signed-off-by: Dmitri Pivkine <[email protected]>
dmitripivkine
changed the title
Sorry, fixed. Thank you! |
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jenkins build all |
babsingh
approved these changes
Oct 30, 2023
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Currently Sparse Virtual Memory uses page size Object Heap is allocated with. We want to use small pages for Sparse Heap always regardless. Also Sparse Virtual Memory uses page flags "requested" for Object Heap. This is the bug. Page flags should be paired with the page size.
Please note, that current MM_SparseVirtualMemory implementation can use double mapping instead of off-heap. This is an experimental feature never used in the code and not planned to be used. This feature uses hidden assumption that memory page size/flags should be the same for Object and Sparse heaps. This PR can break it potentially in the case memory page settings in the Object Heap and Sparse heap are different. We are going to be aware about this if we need another round of experimental testing with double mapping support.