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src/share/vm/gc/g1/g1IHOPControl.hpp
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rev 9431 : dihop-changes
rev 9432 : imported patch sihop-thomas-review
rev 9433 : imported patch erik-jmasa-review
rev 9434 : imported patch fix-evac-failure-needs-stats
rev 9436 : [mq]: 8136678-implement-adaptive-sizing-algorithm-for-IHOP
rev 9438 : imported patch erik-jon-review2
rev 9439 : imported patch further-jon-reviews
rev 9440 : [mq]: mikael-review
@@ -24,10 +24,13 @@
#ifndef SHARE_VM_GC_G1_G1IHOPCONTROL_HPP
#define SHARE_VM_GC_G1_G1IHOPCONTROL_HPP
#include "memory/allocation.hpp"
+#include "utilities/numberSeq.hpp"
+
+class G1Predictions;
// Base class for algorithms that calculate the heap occupancy at which
// concurrent marking should start. This heap usage threshold should be relative
// to old gen size.
class G1IHOPControl : public CHeapObj<mtGC> {
@@ -93,6 +96,55 @@
#ifndef PRODUCT
static void test();
#endif
};
+// This algorithm tries to return a concurrent mark starting occupancy value that
+// makes sure that during marking the given target occupancy is never exceeded,
+// based on predictions of current allocation rate and time periods between
+// initial mark and the first mixed gc.
+class G1AdaptiveIHOPControl : public G1IHOPControl {
+ size_t _heap_reserve_percent; // Percentage of maximum heap capacity we should avoid to touch
+ size_t _heap_waste_percent; // Percentage of free heap that should be considered as waste.
+
+ const G1Predictions * _predictor;
+
+ TruncatedSeq _marking_times_s;
+ TruncatedSeq _allocation_rate_s;
+
+ size_t _last_allocation_bytes; // Most recent mutator allocation since last GC.
+ // The most recent unrestrained size of the young gen. This is used as an additional
+ // factor in the calculation of the threshold, as the threshold is based on
+ // non-young gen occupancy at the end of GC. For the IHOP threshold, we need to
+ // consider the young gen size during that time too.
+ // Since we cannot know what young gen sizes are used in the future, we will just
+ // use the current one. We expect that this one will be one with a fairly large size,
+ // as there is no marking or mixed gc that could impact its size too much.
+ size_t _last_unrestrained_young_size;
+
+ bool have_enough_data_for_prediction() const;
+
+ // The "actual" target threshold the algorithm wants to keep during and at the
+ // end of marking. This is typically lower than the requested threshold, as the
+ // algorithm needs to consider restrictions by the environment.
+ size_t actual_target_threshold() const;
+ protected:
+ virtual double last_marking_length_s() const { return _marking_times_s.last(); }
+ public:
+ G1AdaptiveIHOPControl(double ihop_percent,
+ size_t initial_target_occupancy,
+ G1Predictions const* predictor,
+ size_t heap_reserve_percent, // The percentage of total heap capacity that should not be tapped into.
+ size_t heap_waste_percent); // The percentage of the free space in the heap that we think is not usable for allocation.
+
+ virtual size_t get_conc_mark_start_threshold();
+
+ virtual void update_allocation_info(double allocation_time_s, size_t allocated_bytes, size_t additional_buffer_size);
+ virtual void update_marking_length(double marking_length_s);
+
+ virtual void print();
+#ifndef PRODUCT
+ static void test();
+#endif
+};
+
#endif // SHARE_VM_GC_G1_G1IHOPCONTROL_HPP
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