Mercurial > hg > graal-compiler
diff src/share/vm/memory/padded.inline.hpp @ 17754:d7070f371770
8035815: Cache-align and pad the from card cache
Summary: The from card cache is a very frequently accessed data structure. It is essentially a 2d array of per-region values, one row of values for every GC thread. Pad and align the data structure to avoid false sharing.
Reviewed-by: stefank
author | tschatzl |
---|---|
date | Mon, 24 Mar 2014 15:30:30 +0100 |
parents | 9766f73e770d |
children | 5479cb006184 |
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--- a/src/share/vm/memory/padded.inline.hpp Mon Mar 24 15:30:14 2014 +0100 +++ b/src/share/vm/memory/padded.inline.hpp Mon Mar 24 15:30:30 2014 +0100 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -47,3 +47,32 @@ return aligned_padded_array; } + +template <class T, MEMFLAGS flags, size_t alignment> +T** Padded2DArray<T, flags, alignment>::create_unfreeable(uint rows, uint columns, size_t* allocation_size) { + // Calculate and align the size of the first dimension's table. + size_t table_size = align_size_up_(rows * sizeof(T*), alignment); + // The size of the separate rows. + size_t row_size = align_size_up_(columns * sizeof(T), alignment); + // Total size consists of the indirection table plus the rows. + size_t total_size = table_size + rows * row_size + alignment; + + // Allocate a chunk of memory large enough to allow alignment of the chunk. + void* chunk = AllocateHeap(total_size, flags); + // Clear the allocated memory. + memset(chunk, 0, total_size); + // Align the chunk of memory. + T** result = (T**)align_pointer_up(chunk, alignment); + void* data_start = (void*)((uintptr_t)result + table_size); + + // Fill in the row table. + for (size_t i = 0; i < rows; i++) { + result[i] = (T*)((uintptr_t)data_start + i * row_size); + } + + if (allocation_size != NULL) { + *allocation_size = total_size; + } + + return result; +}