8211425: Allocation of old generation of java heap on alternate memory devices - G1 GC
8202286: Allocation of old generation of Java heap on alternate memory devices
Summary: Enable an experimental feature in HotSpot JVM to allocate old generation of G1 GC on an alternative memory device, such as NV-DIMMs.
Reviewed-by: sangheki, sjohanss
Contributed-by: kishor.kharbas@intel.com
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#include "precompiled.hpp"
#include "gc/g1/g1HeterogeneousCollectorPolicy.hpp"
#include "gc/g1/g1HeterogeneousHeapYoungGenSizer.hpp"
#include "gc/g1/heapRegion.hpp"
G1HeterogeneousHeapYoungGenSizer::G1HeterogeneousHeapYoungGenSizer() : G1YoungGenSizer() {
// will be used later when min and max young size is calculated.
_max_young_length = (uint)(G1HeterogeneousCollectorPolicy::reasonable_max_memory_for_young() / HeapRegion::GrainBytes);
}
// Since heap is sized potentially to larger value accounting for dram + nvdimm, we need to limit
// max young gen size to the available dram.
// Call parent class method first and then adjust sizes based on available dram
void G1HeterogeneousHeapYoungGenSizer::adjust_max_new_size(uint number_of_heap_regions) {
G1YoungGenSizer::adjust_max_new_size(number_of_heap_regions);
adjust_lengths_based_on_dram_memory();
}
void G1HeterogeneousHeapYoungGenSizer::heap_size_changed(uint new_number_of_heap_regions) {
G1YoungGenSizer::heap_size_changed(new_number_of_heap_regions);
adjust_lengths_based_on_dram_memory();
}
void G1HeterogeneousHeapYoungGenSizer::adjust_lengths_based_on_dram_memory() {
_min_desired_young_length = MIN2(_min_desired_young_length, _max_young_length);
_max_desired_young_length = MIN2(_max_desired_young_length, _max_young_length);
}