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MemorySubSpaceSemiSpace.cpp
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MemorySubSpaceSemiSpace.cpp
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/*******************************************************************************
* Copyright (c) 1991, 2020 IBM Corp. and others
*
* This program and the accompanying materials are made available under
* the terms of the Eclipse Public License 2.0 which accompanies this
* distribution and is available at https://www.eclipse.org/legal/epl-2.0/
* or the Apache License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the following
* Secondary Licenses when the conditions for such availability set
* forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
* General Public License, version 2 with the GNU Classpath
* Exception [1] and GNU General Public License, version 2 with the
* OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
*******************************************************************************/
#include <math.h>
#include "omrcfg.h"
#include "modronopt.h"
#include "AllocateDescription.hpp"
#include "EnvironmentBase.hpp"
#include "GCExtensionsBase.hpp"
#include "Heap.hpp"
#include "HeapRegionManager.hpp"
#include "LargeObjectAllocateStats.hpp"
#include "MemoryPool.hpp"
#include "MemorySpace.hpp"
#include "MemorySubSpace.hpp"
#include "MemorySubSpaceRegionIterator.hpp"
#include "MemorySubSpaceSemiSpace.hpp"
#include "ParallelDispatcher.hpp"
#include "PhysicalSubArena.hpp"
#include "Scavenger.hpp"
#if defined(OMR_VALGRIND_MEMCHECK)
#include "MemcheckWrapper.hpp"
#endif /* defined(OMR_VALGRIND_MEMCHECK) */
#if defined(OMR_GC_MODRON_SCAVENGER)
/****************************************
* Allocation
****************************************
*/
void *
MM_MemorySubSpaceSemiSpace::allocateObject(MM_EnvironmentBase *env, MM_AllocateDescription *allocDescription, MM_MemorySubSpace *baseSubSpace, MM_MemorySubSpace *previousSubSpace, bool shouldCollectOnFailure)
{
Trc_MM_MSSSS_allocate_entry(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), this, getName(), baseSubSpace, previousSubSpace, (uintptr_t)shouldCollectOnFailure);
void *addr = NULL;
if (shouldCollectOnFailure) {
Trc_MM_MSSSS_allocate(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), 1);
addr = _memorySubSpaceAllocate->allocateObject(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else {
if(previousSubSpace == _parent) {
Trc_MM_MSSSS_allocate(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), 2);
/* if we are coming from parent (after a Global GC), pass it down to Allocate */
addr = _memorySubSpaceAllocate->allocateObject(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else if (previousSubSpace == this) {
/* if retrying after a recent GC (from allocationRequestFailed), pass it down to Allocate */
Trc_MM_MSSSS_allocate(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), 3);
addr = _memorySubSpaceAllocate->allocateObject(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else {
/* Allocate subspace failed after a recent GC, try parent */
Trc_MM_MSSSS_allocate4(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), (uintptr_t)allocDescription->shouldClimb());
Assert_MM_true(previousSubSpace == _memorySubSpaceAllocate);
if (allocDescription->shouldClimb()) {
addr = _parent->allocateObject(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
}
}
}
Trc_MM_MSSSS_allocate_exit(env->getLanguageVMThread(), "Object", allocDescription->getBytesRequested(), addr);
return addr;
}
void *
MM_MemorySubSpaceSemiSpace::allocationRequestFailed(MM_EnvironmentBase *env, MM_AllocateDescription *allocateDescription, AllocationType allocationType, MM_ObjectAllocationInterface *objectAllocationInterface, MM_MemorySubSpace *baseSubSpace, MM_MemorySubSpace *previousSubSpace)
{
Trc_MM_MSSSS_allocationRequestFailed_entry(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), this, getName(), baseSubSpace, previousSubSpace, (uintptr_t)allocationType);
/* The baseSubSpace in this case isn't really valid - in the event of a scavenge, the baseSubSpace changes. The current subSpace will become the
* base for any restarts
*/
void *addr = NULL;
allocateDescription->saveObjects(env);
if (!env->acquireExclusiveVMAccessForGC(_collector, true, true)) {
allocateDescription->restoreObjects(env);
Trc_MM_MSSSS_allocationRequestFailed(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 1);
addr = allocateGeneric(env, allocateDescription, allocationType, objectAllocationInterface, _memorySubSpaceAllocate);
if(NULL != addr) {
Trc_MM_MSSSS_allocationRequestFailed_exit(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 1, addr);
return addr;
}
allocateDescription->saveObjects(env);
if (!env->acquireExclusiveVMAccessForGC(_collector)) {
allocateDescription->restoreObjects(env);
Trc_MM_MSSSS_allocationRequestFailed(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 2);
addr = allocateGeneric(env, allocateDescription, allocationType, objectAllocationInterface, _memorySubSpaceAllocate);
if(NULL != addr) {
/* Satisfied the allocate after having grabbed exclusive access to perform a GC (without actually performing the GC). Raise
* an event for tracing / verbose to report the occurrence.
*/
reportAcquiredExclusiveToSatisfyAllocate(env, allocateDescription);
Trc_MM_MSSSS_allocationRequestFailed_exit(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 2, addr);
return addr;
}
allocateDescription->saveObjects(env);
}
}
Assert_MM_mustHaveExclusiveVMAccess(env->getOmrVMThread());
reportAllocationFailureStart(env, allocateDescription);
allocateDescription->setAllocationType(allocationType);
/* we will pass this as the target subspace for the restarted allocation because the subspaces will swap, if the collection is
* successful, but not if we backout so we don't know which subspace will allocate until after the collect - our own allocation
* routines will call the correct child subspace.
*
* we might not be the only SemiSpace around (think NUMA). if so, we want to do scavenge on whole new space.
* OMRTODO we might be short-cutting here. more formal approach is to pass allocationRequestFailed to parent and he decides what to do
*/
MM_MemorySubSpace *topLevelMemorySubSpaceNew = getTopLevelMemorySubSpace(MEMORY_TYPE_NEW);
addr = _collector->garbageCollect(env, topLevelMemorySubSpaceNew, allocateDescription, J9MMCONSTANT_IMPLICIT_GC_DEFAULT, objectAllocationInterface, this, NULL);
allocateDescription->restoreObjects(env);
if(NULL != addr) {
reportAllocationFailureEnd(env);
Trc_MM_MSSSS_allocationRequestFailed_exit(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 3, addr);
return addr;
}
/* Potentially a more aggressive collect here */
/* Override the baseSubSpace with this - the allocate subspace can change through collections */
reportAllocationFailureEnd(env);
/*
* TLH: Should we not be checking "collect and climb" here or some such? why are we not calling the parent?
* Calling of parent for TLH is wrong because objects allocated into it on the in-line path won't have the OLD bit set
* CMVC 144061
*/
if (ALLOCATION_TYPE_TLH != allocationType) {
Trc_MM_MSSSS_allocationRequestFailed(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 3);
addr = _parent->allocationRequestFailed(env, allocateDescription, allocationType, objectAllocationInterface, this, this);
}
Trc_MM_MSSSS_allocationRequestFailed_exit(env->getLanguageVMThread(), allocateDescription->getBytesRequested(), 4, addr);
return addr;
}
void *
MM_MemorySubSpaceSemiSpace::allocateArrayletLeaf(MM_EnvironmentBase *env, MM_AllocateDescription *allocDescription, MM_MemorySubSpace *baseSubSpace, MM_MemorySubSpace *previousSubSpace, bool shouldCollectOnFailure)
{
void *addr = NULL;
if (shouldCollectOnFailure) {
addr = _memorySubSpaceAllocate->allocateArrayletLeaf(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else {
if(previousSubSpace == _parent) {
/* if we are coming from parent (after a Global GC), pass it down to Allocate */
addr = _memorySubSpaceAllocate->allocateArrayletLeaf(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else if (previousSubSpace == this) {
/* if retrying after a recent GC (from allocationRequestFailed), pass it down to Allocate */
addr = _memorySubSpaceAllocate->allocateArrayletLeaf(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
} else {
/* Allocate subspace failed after a recent GC, try parent */
Assert_MM_true(previousSubSpace == _memorySubSpaceAllocate);
if (allocDescription->shouldClimb()) {
addr = _parent->allocateArrayletLeaf(env, allocDescription, baseSubSpace, this, shouldCollectOnFailure);
}
}
}
return addr;
}
void *
MM_MemorySubSpaceSemiSpace::allocateTLH(MM_EnvironmentBase *env, MM_AllocateDescription *allocDescription, MM_ObjectAllocationInterface *objectAllocationInterface, MM_MemorySubSpace *baseSubSpace, MM_MemorySubSpace *previousSubSpace, bool shouldCollectOnFailure)
{
/* We may receive this call from the MemorySubSpaceGeneric for which we are the parent but we shouldn't satisfy TLH allocates
* in this space (since that would allow us to fill old space before collecting new space) so just return NULL.
* This call has been observed on Vich configurations, at the very least.
*/
return NULL;
}
/****************************************
* Explicit Collection
****************************************
*/
void
MM_MemorySubSpaceSemiSpace::systemGarbageCollect(MM_EnvironmentBase *env, uint32_t gcCode)
{
if(_collector) {
env->acquireExclusiveVMAccessForGC(_collector);
reportSystemGCStart(env, gcCode);
_collector->garbageCollect(env, this, NULL, gcCode, NULL, NULL, NULL);
/* Handle abort from local collect */
if (_extensions->isScavengerBackOutFlagRaised()) {
_parent->getCollector()->garbageCollect(env, this, NULL, gcCode, NULL, NULL, NULL);
}
reportSystemGCEnd(env);
env->releaseExclusiveVMAccessForGC();
}
}
/**
* If the child subSpace is active return true, else return false.
*/
bool
MM_MemorySubSpaceSemiSpace::isChildActive(MM_MemorySubSpace *memorySubSpace)
{
return memorySubSpace == _memorySubSpaceAllocate;
}
/****************************************
* Sub Space Categorization
****************************************
*/
MM_MemorySubSpace *
MM_MemorySubSpaceSemiSpace::getDefaultMemorySubSpace()
{
return _memorySubSpaceAllocate;
}
bool
MM_MemorySubSpaceSemiSpace::isObjectInEvacuateMemory(omrobjectptr_t objectPtr)
{
/* check if the object in cached allocate (from GC perspective evacuate) ranges */
return ((void *)objectPtr >= _allocateSpaceBase) && ((void *)objectPtr < _allocateSpaceTop);
}
bool
MM_MemorySubSpaceSemiSpace::isObjectInNewSpace(omrobjectptr_t objectPtr)
{
return ((void *)objectPtr >= _survivorSpaceBase) && ((void *)objectPtr < _survivorSpaceTop);
}
bool
MM_MemorySubSpaceSemiSpace::isObjectInNewSpace(void *objectBase, void *objectTop)
{
return (objectBase >= _survivorSpaceBase) && (objectTop <= _survivorSpaceTop);
}
uintptr_t
MM_MemorySubSpaceSemiSpace::getMaxSpaceForObjectInEvacuateMemory(omrobjectptr_t objectPtr)
{
uintptr_t result = 0;
if (isObjectInEvacuateMemory(objectPtr)) {
result = (uintptr_t)_allocateSpaceTop - (uintptr_t)objectPtr;
}
return result;
}
/****************************************
* Free list building
****************************************
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getActiveMemorySize(uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW) {
if (_memorySubSpaceSurvivor == _memorySubSpaceEvacuate) {
return _memorySubSpaceAllocate->getActiveMemorySize() + _memorySubSpaceSurvivor->getActiveMemorySize();
} else if (_memorySubSpaceSurvivor == _memorySubSpaceAllocate) {
return _memorySubSpaceSurvivor->getActiveMemorySize() + _memorySubSpaceEvacuate->getActiveMemorySize();
} else if (_memorySubSpaceEvacuate == _memorySubSpaceAllocate) {
return _memorySubSpaceSurvivor->getActiveMemorySize() + _memorySubSpaceEvacuate->getActiveMemorySize();
} else {
Assert_MM_unreachable();
}
}
return 0;
}
/**
* @copydoc MM_MemorySubSpace::getActualActiveFreeMemorySize()
* The semispace implementation will only report free memory associated to the allocate memory subspace.
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getActualActiveFreeMemorySize()
{
return _memorySubSpaceAllocate->getActualActiveFreeMemorySize();
}
/**
* @copydoc MM_MemorySubSpace::getActualActiveFreeMemorySize(uintptr_t)
* The semispace implementation will only report free memory associated to the allocate memory subspace.
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getActualActiveFreeMemorySize(uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW){
return _memorySubSpaceAllocate->getActualActiveFreeMemorySize();
} else {
return 0;
}
}
/**
* @copydoc MM_MemorySubSpace::getApproximateActiveFreeMemorySize()
* The semispace implementation will only report free memory associated to the allocate memory subspace.
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getApproximateActiveFreeMemorySize()
{
return _memorySubSpaceAllocate->getApproximateActiveFreeMemorySize();
}
/**
* @copydoc MM_MemorySubSpace::getApproximateActiveFreeMemorySize(uintptr_t)
* The semispace implementation will only report free memory associated to the allocate memory subspace.
*/
uintptr_t
MM_MemorySubSpaceSemiSpace::getApproximateActiveFreeMemorySize(uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW){
return _memorySubSpaceAllocate->getApproximateActiveFreeMemorySize();
} else {
return 0;
}
}
uintptr_t
MM_MemorySubSpaceSemiSpace::getActiveSurvivorMemorySize(uintptr_t includeMemoryType)
{
if (getTypeFlags() & MEMORY_TYPE_NEW) {
return _memorySubSpaceSurvivor->getActiveMemorySize(MEMORY_TYPE_NEW);
} else {
return 0;
}
}
uintptr_t
MM_MemorySubSpaceSemiSpace::getApproximateActiveFreeSurvivorMemorySize(uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW){
return _memorySubSpaceSurvivor->getApproximateActiveFreeMemorySize();
} else {
return 0;
}
}
uintptr_t
MM_MemorySubSpaceSemiSpace::getActualActiveFreeSurvivorMemorySize(uintptr_t includeMemoryType)
{
if (getTypeFlags() & MEMORY_TYPE_NEW) {
return _memorySubSpaceSurvivor->getActiveMemorySize(MEMORY_TYPE_NEW);
} else {
return 0;
}
}
void
MM_MemorySubSpaceSemiSpace::abandonHeapChunk(void *addrBase, void *addrTop)
{
Assert_MM_unreachable();
}
/**
*/
void
MM_MemorySubSpaceSemiSpace::mergeHeapStats(MM_HeapStats *heapStats)
{
_memorySubSpaceAllocate->mergeHeapStats(heapStats);
_memorySubSpaceSurvivor->mergeHeapStats(heapStats);
}
void
MM_MemorySubSpaceSemiSpace::mergeHeapStats(MM_HeapStats *heapStats, uintptr_t includeMemoryType)
{
if (includeMemoryType & MEMORY_TYPE_NEW){
_memorySubSpaceAllocate->mergeHeapStats(heapStats);
_memorySubSpaceSurvivor->mergeHeapStats(heapStats);
}
}
/**
* Initialization
*/
MM_MemorySubSpaceSemiSpace *
MM_MemorySubSpaceSemiSpace::newInstance(MM_EnvironmentBase *env, MM_Collector *collector, MM_PhysicalSubArena *physicalSubArena, MM_MemorySubSpace *memorySubSpaceAllocate, MM_MemorySubSpace *memorySubSpaceSurvivor, bool usesGlobalCollector, uintptr_t minimumSize, uintptr_t initialSize, uintptr_t maximumSize)
{
MM_MemorySubSpaceSemiSpace *memorySubSpace;
memorySubSpace = (MM_MemorySubSpaceSemiSpace *)env->getForge()->allocate(sizeof(MM_MemorySubSpaceSemiSpace), OMR::GC::AllocationCategory::FIXED, OMR_GET_CALLSITE());
if (memorySubSpace) {
new(memorySubSpace) MM_MemorySubSpaceSemiSpace(env, collector, physicalSubArena, memorySubSpaceAllocate, memorySubSpaceSurvivor, usesGlobalCollector, minimumSize, initialSize, maximumSize);
if (!memorySubSpace->initialize(env)) {
memorySubSpace->kill(env);
memorySubSpace = NULL;
}
}
return memorySubSpace;
}
bool
MM_MemorySubSpaceSemiSpace::initialize(MM_EnvironmentBase *env)
{
if(!MM_MemorySubSpace::initialize(env)) {
return false;
}
_previousBytesFlipped = getMinimumSize() / 2;
_tiltedAverageBytesFlipped = _previousBytesFlipped;
_tiltedAverageBytesFlippedDelta = _previousBytesFlipped;
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
/* we are clueless about initial allocation rate and its deviation, but small non-zero values
* are still better than 0 values, to help with faster learning of real values.
*/
_avgBytesAllocatedDuringConcurrent = getMinimumSize() / 10;
_deviationBytesAllocatedDuringConcurrent = (float)_avgBytesAllocatedDuringConcurrent / 10;
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
/* register the children */
registerMemorySubSpace(_memorySubSpaceSurvivor);
registerMemorySubSpace(_memorySubSpaceAllocate);
_memorySubSpaceSurvivor->isAllocatable(false);
/* this memoryPool can be used by scavenger, maximum tlh size should be max(_extensions->tlhMaximumSize, _extensions->scavengerScanCacheMaximumSize) */
uintptr_t tlhMaximumSize = OMR_MAX(_extensions->tlhMaximumSize, _extensions->scavengerScanCacheMaximumSize);
_largeObjectAllocateStats = MM_LargeObjectAllocateStats::newInstance(env, (uint16_t)_extensions->largeObjectAllocationProfilingTopK, _extensions->largeObjectAllocationProfilingThreshold, _extensions->largeObjectAllocationProfilingVeryLargeObjectThreshold, (float)_extensions->largeObjectAllocationProfilingSizeClassRatio / (float)100.0,
_extensions->heap->getMaximumMemorySize(), tlhMaximumSize + _extensions->minimumFreeEntrySize, _extensions->tlhMinimumSize);
if (NULL == _largeObjectAllocateStats) {
return false;
}
return true;
}
void
MM_MemorySubSpaceSemiSpace::tearDown(MM_EnvironmentBase *env)
{
MM_MemorySubSpace::tearDown(env);
if (NULL != _largeObjectAllocateStats) {
_largeObjectAllocateStats->kill(env);
_largeObjectAllocateStats = NULL;
}
}
/****************************************
* Type specific functionality
****************************************
*/
void
MM_MemorySubSpaceSemiSpace::flip(MM_EnvironmentBase *env, Flip_step step)
{
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
OMRPORT_ACCESS_FROM_OMRPORT(env->getPortLibrary());
bool debug = _extensions->debugTiltedScavenge;
#endif
switch (step) {
case set_evacuate:
_memorySubSpaceEvacuate = _memorySubSpaceAllocate;
_memorySubSpaceEvacuate->isAllocatable(false);
break;
case set_allocate:
_memorySubSpaceAllocate = _memorySubSpaceSurvivor;
_memorySubSpaceAllocate->isAllocatable(true);
/* Let know MemorySpace about new default MemorySubSpace */
getMemorySpace()->setDefaultMemorySubSpace(getDefaultMemorySubSpace());
break;
case disable_allocation:
_memorySubSpaceAllocate->isAllocatable(false);
break;
case restore_allocation:
_memorySubSpaceAllocate->isAllocatable(true);
break;
case restore_allocation_and_set_survivor:
_memorySubSpaceAllocate->isAllocatable(true);
_memorySubSpaceSurvivor = _memorySubSpaceEvacuate;
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
_bytesAllocatedDuringConcurrent = _extensions->allocationStats.bytesAllocated();
_avgBytesAllocatedDuringConcurrent = (uintptr_t)MM_Math::weightedAverage((float)_avgBytesAllocatedDuringConcurrent,
(float)(_bytesAllocatedDuringConcurrent), 0.7f);
_deviationBytesAllocatedDuringConcurrent = ((float)_bytesAllocatedDuringConcurrent - (float)_avgBytesAllocatedDuringConcurrent);
_avgDeviationBytesAllocatedDuringConcurrent =
sqrtf(MM_Math::weightedAverage(_avgDeviationBytesAllocatedDuringConcurrent * _avgDeviationBytesAllocatedDuringConcurrent,
(float)_deviationBytesAllocatedDuringConcurrent * _deviationBytesAllocatedDuringConcurrent, 0.7f));
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
break;
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
case backout:
Assert_MM_true(_extensions->concurrentScavenger);
/* We have objects on both sides of Nursery. We will unify the two sides and do a compacting slide (after percolate global GC)
* Enforce Allocate be in low address range, since compact slide in percolate global GC moves objects to low addresses.
* Note: _allocateSpaceBase/Top are stale (not updated in set_allocate), since they are overloaded to point to Evacuate during an active cycle
*/
if (_allocateSpaceBase < _survivorSpaceBase) {
_memorySubSpaceAllocate = _memorySubSpaceEvacuate;
_memorySubSpaceEvacuate = _memorySubSpaceSurvivor;
getMemorySpace()->setDefaultMemorySubSpace(getDefaultMemorySubSpace());
if(debug) {
omrtty_printf("tilt backout _allocateSpaceBase/Top %llx/%llx _survivorSpaceBase/Top %llx/%llx tilt sizes %llx %llx\n",
_allocateSpaceBase, _allocateSpaceTop, _survivorSpaceBase, _survivorSpaceTop,
(uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase + (uintptr_t)_survivorSpaceTop - (uintptr_t)_survivorSpaceBase, (uintptr_t)0);
}
} else {
_memorySubSpaceSurvivor = _memorySubSpaceEvacuate;
cacheRanges(_memorySubSpaceAllocate, &_allocateSpaceBase, &_allocateSpaceTop);
cacheRanges(_memorySubSpaceSurvivor, &_survivorSpaceBase, &_survivorSpaceTop);
if(debug) {
omrtty_printf("tilt backout forced flip _allocateSpaceBase/Top %llx/%llx _survivorSpaceBase/Top %llx/%llx tilt sizes %llx %llx\n",
_allocateSpaceBase, _allocateSpaceTop, _survivorSpaceBase, _survivorSpaceTop,
(uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase + (uintptr_t)_survivorSpaceTop - (uintptr_t)_survivorSpaceBase, (uintptr_t)0);
}
}
/* Tilt 100% on PhysicalSubArena level (leave SubSpaces unchanged). Give everything to the low address (Allocate) part */
_physicalSubArena->tilt(env, (uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase + (uintptr_t)_survivorSpaceTop - (uintptr_t)_survivorSpaceBase, (uintptr_t)0, false);
/* disable potentially successful allocation (in case of forced abort) to trigger another (percolate) GC */
_memorySubSpaceAllocate->isAllocatable(false);
getMemorySpace()->getTenureMemorySubSpace()->isAllocatable(false);
break;
case restore_tilt_after_percolate:
{
Assert_MM_true(_extensions->concurrentScavenger);
uintptr_t lastFreeEntrySize = 0;
MM_HeapLinkedFreeHeader *lastFreeEntry = getDefaultMemorySubSpace()->getMemoryPool()->getLastFreeEntry();
if (NULL != lastFreeEntry) {
lastFreeEntrySize = lastFreeEntry->getSize();
if(debug) {
omrtty_printf("tilt restore_tilt_after_percolate last free entry %llx size %llx\n",
lastFreeEntry, lastFreeEntrySize);
}
/* rely on the last free entry only if at the very end of SemiSpace (no objects after it) */
if (((uintptr_t)lastFreeEntry + lastFreeEntrySize) != OMR_MAX((uintptr_t)_allocateSpaceTop, (uintptr_t)_survivorSpaceTop)) {
lastFreeEntrySize = 0;
}
}
/* Make Survivor space from the last free entry in the unified Nursery */
uintptr_t heapAlignedLastFreeEntrySize = MM_Math::roundToFloor(_extensions->heapAlignment, lastFreeEntrySize);
/* Region size is aligned to Concurrent Scavenger Page Section size already */
heapAlignedLastFreeEntrySize = MM_Math::roundToFloor(_extensions->regionSize, heapAlignedLastFreeEntrySize);
if(debug) {
omrtty_printf("tilt restore_tilt_after_percolate heapAlignedLastFreeEntry %llx section (%llx) aligned size %llx\n",
lastFreeEntrySize, _extensions->getConcurrentScavengerPageSectionSize(), heapAlignedLastFreeEntrySize);
}
/* allocate/survivor base/top still hold the values from before when we did 100% tilt */
uintptr_t allocateSize = (uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase;
uintptr_t survivorSize = (uintptr_t)_survivorSpaceTop - (uintptr_t)_survivorSpaceBase;
if (allocateSize < survivorSize) {
allocateSize = survivorSize;
survivorSize = (uintptr_t)_allocateSpaceTop - (uintptr_t)_allocateSpaceBase;
}
if(debug) {
omrtty_printf("tilt restore_tilt_after_percolate allocateSize %llx survivorSize %llx\n", allocateSize, survivorSize);
}
if (heapAlignedLastFreeEntrySize < survivorSize) {
allocateSize += (survivorSize - heapAlignedLastFreeEntrySize);
survivorSize = heapAlignedLastFreeEntrySize;
}
if(debug) {
omrtty_printf("tilt restore_tilt_after_percolate adjusted allocateSize %llx survivorSize %llx\n", allocateSize, survivorSize);
}
tilt(env, allocateSize, survivorSize);
/* Restore allocation, which we had disabled in the backout step */
_memorySubSpaceAllocate->isAllocatable(true);
getMemorySpace()->getTenureMemorySubSpace()->isAllocatable(true);
_extensions->setScavengerBackOutState(backOutFlagCleared);
}
break;
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
default:
Assert_MM_unreachable();
}
}
void
MM_MemorySubSpaceSemiSpace::cacheRanges(MM_MemorySubSpace *subSpace, void **base, void **top)
{
GC_MemorySubSpaceRegionIterator regionIterator(subSpace);
MM_HeapRegionDescriptor* region = regionIterator.nextRegion();
Assert_MM_true(NULL != region);
Assert_MM_true(NULL == regionIterator.nextRegion());
*base = region->getLowAddress();
*top = region->getHighAddress();
}
void
MM_MemorySubSpaceSemiSpace::mainSetupForGC(MM_EnvironmentBase *env)
{
/* cache allocate (effectively evacuate for GC) ranges */
cacheRanges(_memorySubSpaceAllocate, &_allocateSpaceBase, &_allocateSpaceTop);
cacheRanges(_memorySubSpaceSurvivor, &_survivorSpaceBase, &_survivorSpaceTop);
flip(env, set_evacuate);
}
void
MM_MemorySubSpaceSemiSpace::poisonEvacuateSpace()
{
/* poison allocate (effectively effectively evacuate for the caller, GC) */
const uintptr_t pattern = (uintptr_t)-1;
uintptr_t* current = (uintptr_t*) _allocateSpaceBase;
uintptr_t* end = (uintptr_t*) _allocateSpaceTop;
#if defined(OMR_VALGRIND_MEMCHECK)
//clear dead objects before getting their size bits overwritten.
valgrindClearRange(_extensions,(uintptr_t) _allocateSpaceBase, (uintptr_t) _allocateSpaceTop - (uintptr_t) _allocateSpaceBase);
//The space is already dead (objects).... lets redefine so it can be poisoned!
valgrindMakeMemDefined((uintptr_t) _allocateSpaceBase, (uintptr_t) _allocateSpaceTop - (uintptr_t) _allocateSpaceBase);
#endif /* defined(OMR_VALGRIND_MEMCHECK) */
while (current < end) {
*current = pattern;
current += 1;
}
#if defined(OMR_VALGRIND_MEMCHECK)
valgrindMakeMemNoaccess((uintptr_t) _allocateSpaceBase, (uintptr_t) _allocateSpaceTop - (uintptr_t) _allocateSpaceBase);
#endif /* defined(OMR_VALGRIND_MEMCHECK) */
}
void
MM_MemorySubSpaceSemiSpace::tilt(MM_EnvironmentBase *env, uintptr_t allocateSpaceSize, uintptr_t survivorSpaceSize)
{
_physicalSubArena->tilt(env, allocateSpaceSize, survivorSpaceSize);
}
void
MM_MemorySubSpaceSemiSpace::tilt(MM_EnvironmentBase *env, uintptr_t survivorSpaceSizeRatioRequest)
{
_physicalSubArena->tilt(env, survivorSpaceSizeRatioRequest);
}
void
MM_MemorySubSpaceSemiSpace::mainTeardownForSuccessfulGC(MM_EnvironmentBase *env)
{
_memorySubSpaceEvacuate->rebuildFreeList(env);
/* Flip the memory space allocate profile */
if (!_extensions->isConcurrentScavengerEnabled()) {
flip(env, set_allocate);
flip(env, disable_allocation);
}
flip(env, restore_allocation_and_set_survivor);
/* Adjust memory between the semi spaces where applicable */
checkResize(env);
performResize(env);
}
void
MM_MemorySubSpaceSemiSpace::mainTeardownForAbortedGC(MM_EnvironmentBase *env)
{
/* Build free list in survivor. */
if (_extensions->isConcurrentScavengerEnabled()) {
/* There might be live objects in Survivor (newly allocated one since the start of Concurrent Scavenge cycle)
* Sweep in percolate global will rebuild it, so we can skip it here
*/
flip(env, backout);
} else {
_memorySubSpaceSurvivor->rebuildFreeList(env);
/* Restoring allocation after aborted scavenge will probably not help with re-attempts to allocate immediately after an aborted scavenge,
* but still we have to restore it at some point for attempts after percolate GC. It's simplest to do it right away.
*/
flip(env, restore_allocation);
}
}
/**
* Adjust the sub space memory by tilting the split between allocate and survivor space.
*/
void
MM_MemorySubSpaceSemiSpace::checkSubSpaceMemoryPostCollectTilt(MM_EnvironmentBase *env)
{
MM_GCExtensionsBase *extensions = MM_GCExtensionsBase::getExtensions(env->getOmrVM());
if(extensions->tiltedScavenge) {
uintptr_t flipBytes;
uintptr_t flipBytesDelta;
bool debug = extensions->debugTiltedScavenge;
OMRPORT_ACCESS_FROM_OMRPORT(env->getPortLibrary());
uintptr_t currentSize = getTopLevelMemorySubSpace(MEMORY_TYPE_NEW)->getCurrentSize();
if(debug) {
omrtty_printf("\nTilt check:\n");
}
flipBytes = extensions->scavengerStats._flipBytes + extensions->scavengerStats._failedFlipBytes;
if(debug) {
omrtty_printf("\tBytes flip:%zu fail:%zu total:%zu\n",
extensions->scavengerStats._flipBytes,
extensions->scavengerStats._failedFlipBytes,
flipBytes);
}
/* Determine the absolute value of the change in bytes flipped since the last scavenge */
if(flipBytes > _previousBytesFlipped) {
flipBytesDelta = flipBytes - _previousBytesFlipped;
} else {
flipBytesDelta = _previousBytesFlipped - flipBytes;
}
if(debug) {
omrtty_printf("\tflip delta from last (%zu):%zu\n", _previousBytesFlipped, flipBytesDelta);
}
/* Current flip count becomes previous */
_previousBytesFlipped = flipBytes;
/* The average bytes flipped weighted average is more heavily affected if the current size is
* greater than the current average
*/
if(debug) {
omrtty_printf("\tcurrent average bytes flipped: %zu (avg delta %zu)\n",
_tiltedAverageBytesFlipped,
_tiltedAverageBytesFlippedDelta);
}
/* Check if there was any failed to flip objects - which puts us into a bit of a panic mode */
if(0 != extensions->scavengerStats._failedFlipCount) {
/* Panic mode - the current numbers should heavily influence the averages */
if(debug) {
omrtty_printf("\tfailed flip weight\n");
}
_tiltedAverageBytesFlipped = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlipped, (float)flipBytes, 0.0f);
_tiltedAverageBytesFlippedDelta = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlippedDelta, (float)flipBytesDelta, 0.0f);
} else {
/* No panic situation - determine the new tilt ratio through normal means */
if(flipBytes > _tiltedAverageBytesFlipped) {
if(debug) {
omrtty_printf("\tincrease flip weight\n");
}
_tiltedAverageBytesFlipped = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlipped, (float)flipBytes, 0.2f);
_tiltedAverageBytesFlippedDelta = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlippedDelta, (float)flipBytesDelta, 0.2f);
} else {
if(debug) {
omrtty_printf("\tdecrease flip weight\n");
}
_tiltedAverageBytesFlipped = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlipped, (float)flipBytes, 0.8f);
_tiltedAverageBytesFlippedDelta = (uintptr_t)MM_Math::weightedAverage((float)_tiltedAverageBytesFlippedDelta, (float)flipBytesDelta, 0.8f);
}
}
if(debug) {
omrtty_printf("\tnew average bytes flipped: %zu (avg delta %zu)\n",
_tiltedAverageBytesFlipped,
_tiltedAverageBytesFlippedDelta);
}
/* Calculate the desired survivor space ratio */
double survivorSizeAmplification = 1.04 + extensions->dispatcher->threadCount() / 100.0;
double desiredSurvivorSize = (_tiltedAverageBytesFlipped + _tiltedAverageBytesFlippedDelta) * survivorSizeAmplification;
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
if (_extensions->isConcurrentScavengerEnabled()) {
/* Account for mutator allocated objects in hybrid survivor/allocated during concurrent phase of Concurrent Scavenger */
desiredSurvivorSize += _avgBytesAllocatedDuringConcurrent * 1.1
+ extensions->concurrentScavengerAllocDeviationBoost * (uintptr_t)_avgDeviationBytesAllocatedDuringConcurrent
+ extensions->concurrentScavengerSlack;
if (debug) {
omrtty_printf("\tmutator bytesAllocated current %zu average %zu\n", _bytesAllocatedDuringConcurrent, _avgBytesAllocatedDuringConcurrent);
omrtty_printf("\tmutator bytesAllocated deviation current %f average %f (%f%% of average allocation)\n",
_deviationBytesAllocatedDuringConcurrent, _avgDeviationBytesAllocatedDuringConcurrent,
_avgDeviationBytesAllocatedDuringConcurrent * 100 / _avgBytesAllocatedDuringConcurrent);
}
}
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
_desiredSurvivorSpaceRatio = desiredSurvivorSize / currentSize;
if(debug) {
omrtty_printf("\tDesired survivor size: %zu ratio: %zu\n",
(uintptr_t)(currentSize * _desiredSurvivorSpaceRatio), (uintptr_t) (_desiredSurvivorSpaceRatio * 100));
}
/* Sanity check for lowest possible ratio */
if (_desiredSurvivorSpaceRatio < extensions->survivorSpaceMinimumSizeRatio) {
_desiredSurvivorSpaceRatio = extensions->survivorSpaceMinimumSizeRatio;
}
/* Never hand out more than 50% to the survivor */
if (_desiredSurvivorSpaceRatio > extensions->survivorSpaceMaximumSizeRatio) {
_desiredSurvivorSpaceRatio = extensions->survivorSpaceMaximumSizeRatio;
}
/* we have flipped already, so to get old survivor space ratio we fetch allocate size */
double previousSurvivorSpaceRatio = (double) _memorySubSpaceAllocate->getActiveMemorySize() / currentSize;
/* Do not let survivor space shrink by more than the maximum tilt increase */
assume0(previousSurvivorSpaceRatio >= extensions->tiltedScavengeMaximumIncrease);
if (_desiredSurvivorSpaceRatio < (previousSurvivorSpaceRatio - extensions->tiltedScavengeMaximumIncrease)) {
_desiredSurvivorSpaceRatio = previousSurvivorSpaceRatio - extensions->tiltedScavengeMaximumIncrease;
}
if(debug) {
omrtty_printf("\tPrevious survivor ratio: %zu\n", (uintptr_t) (previousSurvivorSpaceRatio * 100));
omrtty_printf("\tAdjusted survivor size: %zu ratio: %zu\n",(uintptr_t)(currentSize * _desiredSurvivorSpaceRatio),
(uintptr_t) (_desiredSurvivorSpaceRatio * 100));
}
}
}
/**
* Adjust the sub space memory by resizing the allocate and survivor space (expand or contract).
*/
void
MM_MemorySubSpaceSemiSpace::checkSubSpaceMemoryPostCollectResize(MM_EnvironmentBase *env)
{
MM_GCExtensionsBase *extensions = MM_GCExtensionsBase::getExtensions(env->getOmrVM());
uintptr_t regionSize = extensions->getHeap()->getHeapRegionManager()->getRegionSize();
MM_Scavenger *scavenger = (MM_Scavenger *)_collector;
if(extensions->dynamicNewSpaceSizing) {
bool doDynamicNewSpaceSizing = true;
bool debug = extensions->debugDynamicNewSpaceSizing;
OMRPORT_ACCESS_FROM_OMRPORT(env->getPortLibrary());
if(debug) {
omrtty_printf("New space resize check:\n");
}
if (extensions->scavengerStats._gcCount == 1){
if(debug) {
omrtty_printf("\tNo previous scavenge - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
/* the wall clock might be shifted backwards externally */
if (scavenger->_cycleTimes.cycleStart < _lastGCEndTime) {
/* clock has been shifted backwards between scavenges */
if(debug) {
omrtty_printf("\tClock shifted backwards between scavenges - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
if (scavenger->_cycleTimes.cycleEnd < scavenger->_cycleTimes.cycleStart) {
/* clock has been shifted backwards at the time of the scavenge */
if(debug) {
omrtty_printf("\tClock shifted backwards at the time of the scavenge - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
uint64_t intervalTime = omrtime_hires_delta(_lastGCEndTime, scavenger->_cycleTimes.cycleEnd, OMRPORT_TIME_DELTA_IN_MICROSECONDS);
if(0 == intervalTime) {
if(debug) {
omrtty_printf("\tInterval time 0 - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
uint64_t scavengeTime = omrtime_hires_delta(scavenger->_cycleTimes.cycleStart, scavenger->_cycleTimes.cycleEnd, OMRPORT_TIME_DELTA_IN_MICROSECONDS );
if(0 == scavengeTime) {
if(debug) {
omrtty_printf("\tScavenge time 0 - ABORTING\n");
}
doDynamicNewSpaceSizing = false;
}
_lastGCEndTime = scavenger->_cycleTimes.cycleEnd;
if (doDynamicNewSpaceSizing) {
double expectedTimeRatio = (extensions->dnssExpectedTimeRatioMaximum + extensions->dnssExpectedTimeRatioMinimum) / 2;
/* Find the ratio of time to scavenge versus the interval time since the last scavenge */
double timeRatio = (double)((int64_t)scavengeTime) / (double)((int64_t) intervalTime);
if(debug) {
omrtty_printf("\tTime scav:%llu interval:%llu ratio:%lf\n", scavengeTime, intervalTime, timeRatio);
}
#if defined(OMR_GC_CONCURRENT_SCAVENGER)
if (_extensions->isConcurrentScavengerEnabled()) {
/* In CS world, we cannot easily measure GC overhead. This is just a simple adjustment, which is somewhat ok for light to medium
* loaded systems. In overloaded systems (where GC background threads are starved and GC prolonged), we may expand more than necessary.
* Multi JVM configuration may skew this even more (perhaps it's better to base it on CPU count, rather than GC thread count?). */
timeRatio = timeRatio * _extensions->concurrentScavengerBackgroundThreads / _extensions->dispatcher->activeThreadCount();
if(debug) {
omrtty_printf("\tCS adjusted ratio:%lf\n", timeRatio);
}
}
#endif /* OMR_GC_CONCURRENT_SCAVENGER */
if(debug) {
omrtty_printf("\tAverage scavenge time ratio: %lf -> ", _averageScavengeTimeRatio);
}
/* Based on the current time ratio versus the average time ratio, determine what weight to assign when
* calculating the new average
*/
double weight;
if(timeRatio > _averageScavengeTimeRatio) {
if(timeRatio > expectedTimeRatio) {
if(timeRatio > extensions->dnssExpectedTimeRatioMaximum) {
weight = extensions->dnssWeightedTimeRatioFactorIncreaseLarge;
} else {
weight = extensions->dnssWeightedTimeRatioFactorIncreaseMedium;
}
} else {
weight = extensions->dnssWeightedTimeRatioFactorIncreaseSmall;
}
} else {
weight = extensions->dnssWeightedTimeRatioFactorDecrease;
}
/* Weight determined - calculate the new average */
_averageScavengeTimeRatio = (timeRatio * weight) + (_averageScavengeTimeRatio * (1.0 - weight));
if(debug) {
omrtty_printf("%lf (weight %lf)\n", _averageScavengeTimeRatio, weight);
}
/* If the average scavenge to interval ratio is greater than the maximum, try to expand */
if((_averageScavengeTimeRatio > extensions->dnssExpectedTimeRatioMaximum)
&& (NULL != _physicalSubArena) && _physicalSubArena->canExpand(env) && (maxExpansionInSpace(env) != 0)) {
double desiredExpansionFactor, adjustedExpansionFactor;
/* Try to reach 50% of the expected time ratio through expansion */
desiredExpansionFactor = _averageScavengeTimeRatio - (expectedTimeRatio / 2);
if (desiredExpansionFactor > extensions->dnssMaximumExpansion) {
adjustedExpansionFactor = extensions->dnssMaximumExpansion;
} else if (desiredExpansionFactor < extensions->dnssMinimumExpansion) {
adjustedExpansionFactor = extensions->dnssMinimumExpansion;
} else {
adjustedExpansionFactor = desiredExpansionFactor;
}
/* Adjust the average scavenge to interval ratio */
_averageScavengeTimeRatio -= adjustedExpansionFactor;
_expansionSize = MM_Math::roundToCeiling(extensions->heapAlignment, (uintptr_t)(getCurrentSize() * adjustedExpansionFactor));
_expansionSize = MM_Math::roundToCeiling(2 * regionSize, _expansionSize);
if(debug) {
omrtty_printf("\tExpand decision - expandFactor desired: %lf adjusted: %lf size: %u\n", desiredExpansionFactor, adjustedExpansionFactor, _expansionSize);
omrtty_printf("\tExpand decision - current size: %d expanded size: %d\n", getCurrentSize(), getCurrentSize() + _expansionSize);
omrtty_printf("\tExpand decision - new time ratio:%lf\n\n\n", _averageScavengeTimeRatio);
}
extensions->heap->getResizeStats()->setLastExpandReason(SCAV_RATIO_TOO_HIGH);
}
/* If the average scavenge to interval ratio is less than the minimum, try to contract */
if(_averageScavengeTimeRatio < extensions->dnssExpectedTimeRatioMinimum
&& (NULL != _physicalSubArena) && _physicalSubArena->canContract(env) && (maxContractionInSpace(env) != 0)) {
double desiredContractionFactor, adjustedContractionFactor;
/* Try to reach 200% of the expected minimum time ratio through contraction */
desiredContractionFactor = OMR_MIN(extensions->dnssExpectedTimeRatioMinimum * 2, expectedTimeRatio);
desiredContractionFactor = desiredContractionFactor - _averageScavengeTimeRatio;
if (desiredContractionFactor > extensions->dnssMaximumContraction) {
adjustedContractionFactor = extensions->dnssMaximumContraction;
} else if (desiredContractionFactor < extensions->dnssMinimumContraction) {
adjustedContractionFactor = extensions->dnssMinimumContraction;
} else {
adjustedContractionFactor = desiredContractionFactor;
}
/* Adjust the average scavenge to interval ratio */
_averageScavengeTimeRatio += adjustedContractionFactor;
_contractionSize = MM_Math::roundToCeiling(extensions->heapAlignment, (uintptr_t)(getCurrentSize() * adjustedContractionFactor));
_contractionSize = MM_Math::roundToCeiling(regionSize, _contractionSize);
if(debug) {
omrtty_printf("\tContract decision - contractFactor desired: %lf adjusted: %lf size: %u\n", desiredContractionFactor, adjustedContractionFactor, _contractionSize);
omrtty_printf("\tContract decision - current size: %d contracted size: %d\n", getCurrentSize(), getCurrentSize() - _contractionSize);