7143511: G1: Another instance of high GC Worker Other time (50ms)
Summary: Tiered compilation has increased the number of nmethods in the code cache. This has, in turn, significantly increased the number of marked nmethods processed during the StrongRootsScope destructor. Create a specialized version of CodeBlobToOopClosure for G1 which places only those nmethods that contain pointers into the collection set on to the marked nmethods list.
Reviewed-by: iveresov, tonyp
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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP
#include "gc_implementation/g1/concurrentMark.inline.hpp"
#include "gc_implementation/g1/g1CollectedHeap.hpp"
#include "gc_implementation/g1/g1OopClosures.hpp"
#include "gc_implementation/g1/g1RemSet.hpp"
/*
* This really ought to be an inline function, but apparently the C++
* compiler sometimes sees fit to ignore inline declarations. Sigh.
*/
// This must a ifdef'ed because the counting it controls is in a
// perf-critical inner loop.
#define FILTERINTOCSCLOSURE_DOHISTOGRAMCOUNT 0
template <class T>
inline void FilterIntoCSClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop) &&
_g1->obj_in_cs(oopDesc::decode_heap_oop_not_null(heap_oop))) {
_oc->do_oop(p);
#if FILTERINTOCSCLOSURE_DOHISTOGRAMCOUNT
if (_dcto_cl != NULL)
_dcto_cl->incr_count();
#endif
}
}
#define FILTEROUTOFREGIONCLOSURE_DOHISTOGRAMCOUNT 0
template <class T>
inline void FilterOutOfRegionClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
HeapWord* obj_hw = (HeapWord*)oopDesc::decode_heap_oop_not_null(heap_oop);
if (obj_hw < _r_bottom || obj_hw >= _r_end) {
_oc->do_oop(p);
#if FILTEROUTOFREGIONCLOSURE_DOHISTOGRAMCOUNT
_out_of_region++;
#endif
}
}
}
// This closure is applied to the fields of the objects that have just been copied.
template <class T>
inline void G1ParScanClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
if (_g1->in_cset_fast_test(obj)) {
// We're not going to even bother checking whether the object is
// already forwarded or not, as this usually causes an immediate
// stall. We'll try to prefetch the object (for write, given that
// we might need to install the forwarding reference) and we'll
// get back to it when pop it from the queue
Prefetch::write(obj->mark_addr(), 0);
Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
// slightly paranoid test; I'm trying to catch potential
// problems before we go into push_on_queue to know where the
// problem is coming from
assert((obj == oopDesc::load_decode_heap_oop(p)) ||
(obj->is_forwarded() &&
obj->forwardee() == oopDesc::load_decode_heap_oop(p)),
"p should still be pointing to obj or to its forwardee");
_par_scan_state->push_on_queue(p);
} else {
_par_scan_state->update_rs(_from, p, _par_scan_state->queue_num());
}
}
}
template <class T>
inline void G1ParPushHeapRSClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
if (_g1->in_cset_fast_test(obj)) {
Prefetch::write(obj->mark_addr(), 0);
Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
// Place on the references queue
_par_scan_state->push_on_queue(p);
}
}
}
template <class T>
inline void G1CMOopClosure::do_oop_nv(T* p) {
assert(_g1h->is_in_g1_reserved((HeapWord*) p), "invariant");
assert(!_g1h->is_on_master_free_list(
_g1h->heap_region_containing((HeapWord*) p)), "invariant");
oop obj = oopDesc::load_decode_heap_oop(p);
if (_cm->verbose_high()) {
gclog_or_tty->print_cr("[%d] we're looking at location "
"*"PTR_FORMAT" = "PTR_FORMAT,
_task->task_id(), p, (void*) obj);
}
_task->deal_with_reference(obj);
}
template <class T>
inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
T heap_oop = oopDesc::load_heap_oop(p);
if (!oopDesc::is_null(heap_oop)) {
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
HeapRegion* hr = _g1h->heap_region_containing((HeapWord*) obj);
if (hr != NULL) {
_cm->grayRoot(obj, obj->size(), _worker_id, hr);
}
}
}
template <class T>
inline void G1Mux2Closure::do_oop_nv(T* p) {
// Apply first closure; then apply the second.
_c1->do_oop(p);
_c2->do_oop(p);
}
template <class T>
inline void G1TriggerClosure::do_oop_nv(T* p) {
// Record that this closure was actually applied (triggered).
_triggered = true;
}
template <class T>
inline void G1InvokeIfNotTriggeredClosure::do_oop_nv(T* p) {
if (!_trigger_cl->triggered()) {
_oop_cl->do_oop(p);
}
}
template <class T>
inline void G1UpdateRSOrPushRefOopClosure::do_oop_nv(T* p) {
oop obj = oopDesc::load_decode_heap_oop(p);
#ifdef ASSERT
// can't do because of races
// assert(obj == NULL || obj->is_oop(), "expected an oop");
// Do the safe subset of is_oop
if (obj != NULL) {
#ifdef CHECK_UNHANDLED_OOPS
oopDesc* o = obj.obj();
#else
oopDesc* o = obj;
#endif // CHECK_UNHANDLED_OOPS
assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
}
#endif // ASSERT
assert(_from != NULL, "from region must be non-NULL");
HeapRegion* to = _g1->heap_region_containing(obj);
if (to != NULL && _from != to) {
// The _record_refs_into_cset flag is true during the RSet
// updating part of an evacuation pause. It is false at all
// other times:
// * rebuilding the rembered sets after a full GC
// * during concurrent refinement.
// * updating the remembered sets of regions in the collection
// set in the event of an evacuation failure (when deferred
// updates are enabled).
if (_record_refs_into_cset && to->in_collection_set()) {
// We are recording references that point into the collection
// set and this particular reference does exactly that...
// If the referenced object has already been forwarded
// to itself, we are handling an evacuation failure and
// we have already visited/tried to copy this object
// there is no need to retry.
if (!self_forwarded(obj)) {
assert(_push_ref_cl != NULL, "should not be null");
// Push the reference in the refs queue of the G1ParScanThreadState
// instance for this worker thread.
_push_ref_cl->do_oop(p);
}
// Deferred updates to the CSet are either discarded (in the normal case),
// or processed (if an evacuation failure occurs) at the end
// of the collection.
// See G1RemSet::cleanup_after_oops_into_collection_set_do().
} else {
// We either don't care about pushing references that point into the
// collection set (i.e. we're not during an evacuation pause) _or_
// the reference doesn't point into the collection set. Either way
// we add the reference directly to the RSet of the region containing
// the referenced object.
_g1_rem_set->par_write_ref(_from, p, _worker_i);
}
}
}
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP