archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-27 06:45:07 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

6672698: mangle_unused_area() should not remangle the entire heap at each collection

Browse source 
Maintain a high water mark for the allocations in a space and mangle only up to that high water mark.

Reviewed-by: ysr, apetrusenko
This commit is contained in:
Jon Masamitsu 2008-07-09 15:08:55 -07:00
parent 0d9452401c
commit 18dbebd143
43 changed files with 1299 additions and 206 deletions
Download patch file Download diff file Expand all files Collapse all files

42
hotspot/src/share/vm/gc_implementation/parallelScavenge/psOldGen.cpp
View file

@ -87,6 +87,15 @@ void PSOldGen::initialize_work(const char* perf_data_name, int level) {
MemRegion cmr((HeapWord*)virtual_space()->low(),
(HeapWord*)virtual_space()->high());
if (ZapUnusedHeapArea) {
// Mangle newly committed space immediately rather than
// waiting for the initialization of the space even though
// mangling is related to spaces. Doing it here eliminates
// the need to carry along information that a complete mangling
// (bottom to end) needs to be done.
SpaceMangler::mangle_region(cmr);
}
Universe::heap()->barrier_set()->resize_covered_region(cmr);
CardTableModRefBS* _ct = (CardTableModRefBS*)Universe::heap()->barrier_set();
@ -112,7 +121,9 @@ void PSOldGen::initialize_work(const char* perf_data_name, int level) {
if (_object_space == NULL)
vm_exit_during_initialization("Could not allocate an old gen space");
object_space()->initialize(cmr, true);
object_space()->initialize(cmr,
SpaceDecorator::Clear,
SpaceDecorator::Mangle);
_object_mark_sweep = new PSMarkSweepDecorator(_object_space, start_array(), MarkSweepDeadRatio);
@ -232,6 +243,19 @@ bool PSOldGen::expand_by(size_t bytes) {
assert_locked_or_safepoint(Heap_lock);
bool result = virtual_space()->expand_by(bytes);
if (result) {
if (ZapUnusedHeapArea) {
// We need to mangle the newly expanded area. The memregion spans
// end -> new_end, we assume that top -> end is already mangled.
// Do the mangling before post_resize() is called because
// the space is available for allocation after post_resize();
HeapWord* const virtual_space_high = (HeapWord*) virtual_space()->high();
assert(object_space()->end() < virtual_space_high,
"Should be true before post_resize()");
MemRegion mangle_region(object_space()->end(), virtual_space_high);
// Note that the object space has not yet been updated to
// coincede with the new underlying virtual space.
SpaceMangler::mangle_region(mangle_region);
}
post_resize();
if (UsePerfData) {
_space_counters->update_capacity();
@ -348,16 +372,7 @@ void PSOldGen::post_resize() {
start_array()->set_covered_region(new_memregion);
Universe::heap()->barrier_set()->resize_covered_region(new_memregion);
// Did we expand?
HeapWord* const virtual_space_high = (HeapWord*) virtual_space()->high();
if (object_space()->end() < virtual_space_high) {
// We need to mangle the newly expanded area. The memregion spans
// end -> new_end, we assume that top -> end is already mangled.
// This cannot be safely tested for, as allocation may be taking
// place.
MemRegion mangle_region(object_space()->end(), virtual_space_high);
object_space()->mangle_region(mangle_region);
}
// ALWAYS do this last!!
object_space()->set_end(virtual_space_high);
@ -462,3 +477,10 @@ void PSOldGen::verify_object_start_array() {
VerifyObjectStartArrayClosure check( this, &_start_array );
object_iterate(&check);
}
#ifndef PRODUCT
void PSOldGen::record_spaces_top() {
assert(ZapUnusedHeapArea, "Not mangling unused space");
object_space()->set_top_for_allocations();
}
#endif