--- old/src/share/vm/gc_implementation/parallelScavenge/generationSizer.cpp 2015-03-26 10:24:09.734936719 +0100 +++ new/src/share/vm/gc_implementation/parallelScavenge/generationSizer.cpp 2015-03-26 10:24:09.660934589 +0100 @@ -66,9 +66,10 @@ void GenerationSizer::initialize_size_info() { trace_gen_sizes("ps heap raw"); - const size_t page_sz = os::page_size_for_region(_min_heap_byte_size, - _max_heap_byte_size, - 8); + const size_t max_page_sz = os::page_size_for_region(_max_heap_byte_size, 8); + const size_t min_pages = 4; // 1 for eden + 1 for each survivor + 1 for old + const size_t min_page_sz = os::page_size_for_region(_min_heap_byte_size, min_pages); + const size_t page_sz = MIN2(max_page_sz, min_page_sz); // Can a page size be something else than a power of two? assert(is_power_of_2((intptr_t)page_sz), "must be a power of 2");