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src/hotspot/share/gc/shenandoah/heuristics/shenandoahStaticHeuristics.cpp

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rev 57681 : 8237570: Shenandoah: cleanup uses of allocation/free threshold in static heuristics
Reviewed-by: XXX


  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 
  27 #include "gc/shenandoah/heuristics/shenandoahStaticHeuristics.hpp"
  28 #include "gc/shenandoah/shenandoahCollectionSet.hpp"
  29 #include "gc/shenandoah/shenandoahFreeSet.hpp"
  30 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
  31 #include "logging/log.hpp"
  32 #include "logging/logTag.hpp"
  33 
  34 ShenandoahStaticHeuristics::ShenandoahStaticHeuristics() : ShenandoahHeuristics() {
  35   // Static heuristics may degrade to continuous if live data is larger
  36   // than free threshold. ShenandoahAllocationThreshold is supposed to break this,
  37   // but it only works if it is non-zero.
  38   SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahAllocationThreshold, 1);
  39 
  40   SHENANDOAH_ERGO_ENABLE_FLAG(ExplicitGCInvokesConcurrent);
  41   SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahImplicitGCInvokesConcurrent);
  42 
  43   // Final configuration checks
  44   SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier);
  45   SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier);
  46   SHENANDOAH_CHECK_FLAG_SET(ShenandoahKeepAliveBarrier);
  47   SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier);
  48   SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier);
  49 }
  50 
  51 ShenandoahStaticHeuristics::~ShenandoahStaticHeuristics() {}
  52 
  53 bool ShenandoahStaticHeuristics::should_start_gc() const {
  54   ShenandoahHeap* heap = ShenandoahHeap::heap();
  55 
  56   size_t capacity = heap->max_capacity();
  57   size_t available = heap->free_set()->available();
  58   size_t threshold_available = capacity / 100 * ShenandoahFreeThreshold;
  59 
  60   if (available < threshold_available) {
  61     log_info(gc)("Trigger: Free (" SIZE_FORMAT "%s) is below free threshold (" SIZE_FORMAT "%s)",
  62                  byte_size_in_proper_unit(available),           proper_unit_for_byte_size(available),
  63                  byte_size_in_proper_unit(threshold_available), proper_unit_for_byte_size(threshold_available));
  64     return true;
  65   }
  66   return ShenandoahHeuristics::should_start_gc();
  67 }
  68 
  69 void ShenandoahStaticHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset,
  70                                                                        RegionData* data, size_t size,
  71                                                                        size_t free) {
  72   size_t threshold = ShenandoahHeapRegion::region_size_bytes() * ShenandoahGarbageThreshold / 100;
  73 
  74   for (size_t idx = 0; idx < size; idx++) {
  75     ShenandoahHeapRegion* r = data[idx]._region;
  76     if (r->garbage() > threshold) {
  77       cset->add_region(r);
  78     }
  79   }
  80 }
  81 


  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 
  27 #include "gc/shenandoah/heuristics/shenandoahStaticHeuristics.hpp"
  28 #include "gc/shenandoah/shenandoahCollectionSet.hpp"
  29 #include "gc/shenandoah/shenandoahFreeSet.hpp"
  30 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
  31 #include "logging/log.hpp"
  32 #include "logging/logTag.hpp"
  33 
  34 ShenandoahStaticHeuristics::ShenandoahStaticHeuristics() : ShenandoahHeuristics() {





  35   SHENANDOAH_ERGO_ENABLE_FLAG(ExplicitGCInvokesConcurrent);
  36   SHENANDOAH_ERGO_ENABLE_FLAG(ShenandoahImplicitGCInvokesConcurrent);
  37 
  38   // Final configuration checks
  39   SHENANDOAH_CHECK_FLAG_SET(ShenandoahLoadRefBarrier);
  40   SHENANDOAH_CHECK_FLAG_SET(ShenandoahSATBBarrier);
  41   SHENANDOAH_CHECK_FLAG_SET(ShenandoahKeepAliveBarrier);
  42   SHENANDOAH_CHECK_FLAG_SET(ShenandoahCASBarrier);
  43   SHENANDOAH_CHECK_FLAG_SET(ShenandoahCloneBarrier);
  44 }
  45 
  46 ShenandoahStaticHeuristics::~ShenandoahStaticHeuristics() {}
  47 
  48 bool ShenandoahStaticHeuristics::should_start_gc() const {
  49   ShenandoahHeap* heap = ShenandoahHeap::heap();
  50 
  51   size_t capacity = heap->max_capacity();
  52   size_t available = heap->free_set()->available();
  53   size_t threshold_available = capacity / 100 * ShenandoahMinFreeThreshold;
  54 
  55   if (available < threshold_available) {
  56     log_info(gc)("Trigger: Free (" SIZE_FORMAT "%s) is below minimum threshold (" SIZE_FORMAT "%s)",
  57                  byte_size_in_proper_unit(available),           proper_unit_for_byte_size(available),
  58                  byte_size_in_proper_unit(threshold_available), proper_unit_for_byte_size(threshold_available));
  59     return true;
  60   }
  61   return ShenandoahHeuristics::should_start_gc();
  62 }
  63 
  64 void ShenandoahStaticHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset,
  65                                                                        RegionData* data, size_t size,
  66                                                                        size_t free) {
  67   size_t threshold = ShenandoahHeapRegion::region_size_bytes() * ShenandoahGarbageThreshold / 100;
  68 
  69   for (size_t idx = 0; idx < size; idx++) {
  70     ShenandoahHeapRegion* r = data[idx]._region;
  71     if (r->garbage() > threshold) {
  72       cset->add_region(r);
  73     }
  74   }
  75 }
  76 
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