--- /dev/null 2018-04-05 19:09:31.849588610 +0200 +++ new/src/hotspot/share/gc/epsilon/epsilonHeap.cpp 2018-04-26 19:34:12.024492689 +0200 @@ -0,0 +1,206 @@ +/* + * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "gc/epsilon/epsilonHeap.hpp" +#include "gc/epsilon/epsilonMemoryPool.hpp" +#include "memory/allocation.hpp" +#include "memory/allocation.inline.hpp" +#include "memory/resourceArea.hpp" + +jint EpsilonHeap::initialize() { + size_t init_byte_size = _policy->initial_heap_byte_size(); + size_t max_byte_size = _policy->max_heap_byte_size(); + size_t align = _policy->heap_alignment(); + + ReservedSpace heap_rs = Universe::reserve_heap(max_byte_size, align); + _virtual_space.initialize(heap_rs, init_byte_size); + + MemRegion committed_region((HeapWord*)_virtual_space.low(), (HeapWord*)_virtual_space.high()); + MemRegion reserved_region((HeapWord*)_virtual_space.low_boundary(), (HeapWord*)_virtual_space.high_boundary()); + + initialize_reserved_region(reserved_region.start(), reserved_region.end()); + + _space = new ContiguousSpace(); + _space->initialize(committed_region, true, true); + + BarrierSet::set_barrier_set(new EpsilonBarrierSet()); + + _max_tlab_size = MIN2(CollectedHeap::max_tlab_size(), EpsilonMaxTLABSize / HeapWordSize); + + _monitoring_support = new EpsilonMonitoringSupport(this); + _last_counter_update = 0; + _last_heap_print = 0; + + _step_counter_update = MIN2(max_byte_size / 16, EpsilonUpdateCountersStep); + _step_heap_print = (EpsilonPrintHeapStep == 0) ? SIZE_MAX : (max_byte_size / EpsilonPrintHeapStep); + + if (init_byte_size != max_byte_size) { + log_info(gc)("Initialized with " SIZE_FORMAT "M heap, resizeable to up to " SIZE_FORMAT "M heap with " SIZE_FORMAT "M steps", + init_byte_size / M, max_byte_size / M, EpsilonMinHeapExpand / M); + } else { + log_info(gc)("Initialized with " SIZE_FORMAT "M non-resizeable heap", init_byte_size / M); + } + if (UseTLAB) { + log_info(gc)("Using TLAB allocation; min: " SIZE_FORMAT "K, max: " SIZE_FORMAT "K", + ThreadLocalAllocBuffer::min_size() * HeapWordSize / K, + _max_tlab_size*HeapWordSize / K); + } else { + log_info(gc)("Not using TLAB allocation"); + } + + return JNI_OK; +} + +void EpsilonHeap::post_initialize() { + CollectedHeap::post_initialize(); +} + +void EpsilonHeap::initialize_serviceability() { + _pool = new EpsilonMemoryPool(this); + _memory_manager.add_pool(_pool); +} + +GrowableArray EpsilonHeap::memory_managers() { + GrowableArray memory_managers(1); + memory_managers.append(&_memory_manager); + return memory_managers; +} + +GrowableArray EpsilonHeap::memory_pools() { + GrowableArray memory_pools(1); + memory_pools.append(_pool); + return memory_pools; +} + +size_t EpsilonHeap::unsafe_max_tlab_alloc(Thread* thr) const { + // This is the only way we can control TLAB sizes without having safepoints. + // Implement exponential expansion within [MinTLABSize; _max_tlab_size], based + // on previously "used" TLAB size. + + size_t size = MIN2(_max_tlab_size * HeapWordSize, MAX2(MinTLABSize, thr->tlab().used() * HeapWordSize * 2)); + + if (log_is_enabled(Trace, gc)) { + ResourceMark rm; + log_trace(gc)( + "Selecting TLAB size for \"%s\" (Desired: " SIZE_FORMAT "K, Used: " SIZE_FORMAT "K) -> " SIZE_FORMAT "K", + Thread::current()->name(), + thr->tlab().desired_size() * HeapWordSize / K, + thr->tlab().used() * HeapWordSize / K, + size / K); + } + + return size; +} + +EpsilonHeap* EpsilonHeap::heap() { + CollectedHeap* heap = Universe::heap(); + assert(heap != NULL, "Uninitialized access to EpsilonHeap::heap()"); + assert(heap->kind() == CollectedHeap::Epsilon, "Not an Epsilon heap"); + return (EpsilonHeap*)heap; +} + +HeapWord* EpsilonHeap::allocate_work(size_t size) { + HeapWord* res = _space->par_allocate(size); + + while (res == NULL) { + // Allocation failed, attempt expansion, and retry: + MutexLockerEx ml(Heap_lock); + + size_t space_left = max_capacity() - capacity(); + size_t want_space = MAX2(size, EpsilonMinHeapExpand); + + if (want_space < space_left) { + // Enough space to expand in bulk: + bool expand = _virtual_space.expand_by(want_space); + assert(expand, "Should be able to expand"); + } else if (size < space_left) { + // No space to expand in bulk, and this allocation is still possible, + // take all the space left: + bool expand = _virtual_space.expand_by(space_left); + assert(expand, "Should be able to expand"); + } else { + // No space left: + return NULL; + } + + _space->set_end((HeapWord *) _virtual_space.high()); + res = _space->par_allocate(size); + } + + size_t used = _space->used(); + if (used - _last_counter_update >= _step_counter_update) { + _last_counter_update = used; + _monitoring_support->update_counters(); + } + + if (used - _last_heap_print >= _step_heap_print) { + log_info(gc)("Heap: " SIZE_FORMAT "M reserved, " SIZE_FORMAT "M committed, " SIZE_FORMAT "M used", + max_capacity() / M, capacity() / M, used / M); + _last_heap_print = used; + } + + return res; +} + +HeapWord* EpsilonHeap::allocate_new_tlab(size_t size) { + return allocate_work(size); +} + +HeapWord* EpsilonHeap::mem_allocate(size_t size, bool *gc_overhead_limit_was_exceeded) { + *gc_overhead_limit_was_exceeded = false; + return allocate_work(size); +} + +void EpsilonHeap::collect(GCCause::Cause cause) { + log_info(gc)("GC request for \"%s\" is ignored", GCCause::to_string(cause)); + _monitoring_support->update_counters(); +} + +void EpsilonHeap::do_full_collection(bool clear_all_soft_refs) { + log_info(gc)("Full GC request for \"%s\" is ignored", GCCause::to_string(gc_cause())); + _monitoring_support->update_counters(); +} + +void EpsilonHeap::safe_object_iterate(ObjectClosure *cl) { + _space->safe_object_iterate(cl); +} + +void EpsilonHeap::print_on(outputStream *st) const { + st->print_cr("Epsilon Heap"); + + // Cast away constness: + ((VirtualSpace)_virtual_space).print_on(st); + + st->print_cr("Allocation space:"); + _space->print_on(st); +} + +void EpsilonHeap::print_tracing_info() const { + Log(gc) log; + size_t allocated_kb = used() / K; + log.info("Total allocated: " SIZE_FORMAT " KB", + allocated_kb); + log.info("Average allocation rate: " SIZE_FORMAT " KB/sec", + (size_t)(allocated_kb * NANOSECS_PER_SEC / os::elapsed_counter())); +}