8031323: Optionally align objects copied to survivor spaces
Reviewed-by: brutisso, tschatzl
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* under the terms of the GNU General Public License version 2 only, as
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*
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#include "precompiled.hpp"
#include "gc_implementation/parallelScavenge/generationSizer.hpp"
#include "memory/collectorPolicy.hpp"
void GenerationSizer::trace_gen_sizes(const char* const str) {
if (TracePageSizes) {
tty->print_cr("%s: " SIZE_FORMAT "," SIZE_FORMAT " "
SIZE_FORMAT "," SIZE_FORMAT " "
SIZE_FORMAT,
str,
_min_old_size / K, _max_old_size / K,
_min_young_size / K, _max_young_size / K,
_max_heap_byte_size / K);
}
}
void GenerationSizer::initialize_alignments() {
_space_alignment = _gen_alignment = default_gen_alignment();
_heap_alignment = compute_heap_alignment();
}
void GenerationSizer::initialize_flags() {
// Do basic sizing work
GenCollectorPolicy::initialize_flags();
assert(UseSerialGC ||
!FLAG_IS_DEFAULT(ParallelGCThreads) ||
(ParallelGCThreads > 0),
"ParallelGCThreads should be set before flag initialization");
// The survivor ratio's are calculated "raw", unlike the
// default gc, which adds 2 to the ratio value. We need to
// make sure the values are valid before using them.
if (MinSurvivorRatio < 3) {
FLAG_SET_ERGO(uintx, MinSurvivorRatio, 3);
}
if (InitialSurvivorRatio < 3) {
FLAG_SET_ERGO(uintx, InitialSurvivorRatio, 3);
}
}
void GenerationSizer::initialize_size_info() {
trace_gen_sizes("ps heap raw");
const size_t page_sz = os::page_size_for_region(_min_heap_byte_size,
_max_heap_byte_size,
8);
// Can a page size be something else than a power of two?
assert(is_power_of_2((intptr_t)page_sz), "must be a power of 2");
size_t new_alignment = round_to(page_sz, _gen_alignment);
if (new_alignment != _gen_alignment) {
_gen_alignment = new_alignment;
_space_alignment = new_alignment;
// Redo everything from the start
initialize_flags();
}
GenCollectorPolicy::initialize_size_info();
trace_gen_sizes("ps heap rnd");
}