1.1 --- a/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp Thu Jan 30 14:05:07 2014 -0800
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp Wed Jan 29 23:17:05 2014 +0100
1.3 @@ -23,6 +23,7 @@
1.4 */
1.5
1.6 #include "precompiled.hpp"
1.7 +#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
1.8 #include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp"
1.9 #include "gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp"
1.10 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
1.11 @@ -76,6 +77,38 @@
1.12 _old_gen_policy_is_ready = false;
1.13 }
1.14
1.15 +size_t PSAdaptiveSizePolicy::calculate_free_based_on_live(size_t live, uintx ratio_as_percentage) {
1.16 + // We want to calculate how much free memory there can be based on the
1.17 + // amount of live data currently in the old gen. Using the formula:
1.18 + // ratio * (free + live) = free
1.19 + // Some equation solving later we get:
1.20 + // free = (live * ratio) / (1 - ratio)
1.21 +
1.22 + const double ratio = ratio_as_percentage / 100.0;
1.23 + const double ratio_inverse = 1.0 - ratio;
1.24 + const double tmp = live * ratio;
1.25 + size_t free = (size_t)(tmp / ratio_inverse);
1.26 +
1.27 + return free;
1.28 +}
1.29 +
1.30 +size_t PSAdaptiveSizePolicy::calculated_old_free_size_in_bytes() const {
1.31 + size_t free_size = (size_t)(_promo_size + avg_promoted()->padded_average());
1.32 + size_t live = ParallelScavengeHeap::heap()->old_gen()->used_in_bytes();
1.33 +
1.34 + if (MinHeapFreeRatio != 0) {
1.35 + size_t min_free = calculate_free_based_on_live(live, MinHeapFreeRatio);
1.36 + free_size = MAX2(free_size, min_free);
1.37 + }
1.38 +
1.39 + if (MaxHeapFreeRatio != 100) {
1.40 + size_t max_free = calculate_free_based_on_live(live, MaxHeapFreeRatio);
1.41 + free_size = MIN2(max_free, free_size);
1.42 + }
1.43 +
1.44 + return free_size;
1.45 +}
1.46 +
1.47 void PSAdaptiveSizePolicy::major_collection_begin() {
1.48 // Update the interval time
1.49 _major_timer.stop();
1.50 @@ -1292,3 +1325,18 @@
1.51 st,
1.52 PSScavenge::tenuring_threshold());
1.53 }
1.54 +
1.55 +#ifndef PRODUCT
1.56 +
1.57 +void TestOldFreeSpaceCalculation_test() {
1.58 + assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 20) == 25, "Calculation of free memory failed");
1.59 + assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 50) == 100, "Calculation of free memory failed");
1.60 + assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 60) == 150, "Calculation of free memory failed");
1.61 + assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(100, 75) == 300, "Calculation of free memory failed");
1.62 + assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 20) == 100, "Calculation of free memory failed");
1.63 + assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 50) == 400, "Calculation of free memory failed");
1.64 + assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 60) == 600, "Calculation of free memory failed");
1.65 + assert(PSAdaptiveSizePolicy::calculate_free_based_on_live(400, 75) == 1200, "Calculation of free memory failed");
1.66 +}
1.67 +
1.68 +#endif /* !PRODUCT */
