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8303883: Confusing parameter name in G1UpdateRemSetTrackingBeforeRebuild::distribute_marked_bytes

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Reviewed-by: ayang, iwalulya
This commit is contained in:
Thomas Schatzl 2023-03-13 11:06:20 +00:00
parent 25e7ac226a
commit 805a4e6806
2 changed files with 29 additions and 28 deletions
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47
src/hotspot/share/gc/g1/g1ConcurrentMark.cpp
View File

@ -606,7 +606,7 @@ private:
if (is_clear_concurrent_undo()) {
// No need to clear bitmaps for empty regions (which includes regions we
// did not mark through).
if (_cm->live_words(r->hrm_index()) == 0) {
if (!_cm->contains_live_object(r->hrm_index())) {
assert(_bitmap->get_next_marked_addr(r->bottom(), r->end()) == r->end(), "Should not have marked bits");
return r->bottom();
}
@ -1109,7 +1109,7 @@ class G1UpdateRemSetTrackingBeforeRebuildTask : public WorkerTask {
bool selected_for_rebuild;
if (hr->is_humongous()) {
bool const is_live = _cm->live_words(hr->humongous_start_region()->hrm_index()) > 0;
bool const is_live = _cm->contains_live_object(hr->humongous_start_region()->hrm_index());
selected_for_rebuild = tracking_policy->update_humongous_before_rebuild(hr, is_live);
} else {
size_t const live_bytes = _cm->live_bytes(hr->hrm_index());
@ -1121,49 +1121,50 @@ class G1UpdateRemSetTrackingBeforeRebuildTask : public WorkerTask {
_cm->update_top_at_rebuild_start(hr);
}
// Distribute the given words across the humongous object starting with hr and
// note end of marking.
void distribute_marked_bytes(HeapRegion* hr, size_t marked_words) {
// Distribute the given marked bytes across the humongous object starting
// with hr and note end of marking for these regions.
void distribute_marked_bytes(HeapRegion* hr, size_t marked_bytes) {
uint const region_idx = hr->hrm_index();
size_t const obj_size_in_words = cast_to_oop(hr->bottom())->size();
uint const num_regions_in_humongous = (uint)G1CollectedHeap::humongous_obj_size_in_regions(obj_size_in_words);
// "Distributing" zero words means that we only note end of marking for these
// regions.
assert(marked_words == 0 || obj_size_in_words == marked_words,
"Marked words should either be 0 or the same as humongous object (" SIZE_FORMAT ") but is " SIZE_FORMAT,
obj_size_in_words, marked_words);
assert(marked_bytes == 0 || obj_size_in_words * HeapWordSize == marked_bytes,
"Marked bytes should either be 0 or the same as humongous object (%zu) but is %zu",
obj_size_in_words * HeapWordSize, marked_bytes);
for (uint i = region_idx; i < (region_idx + num_regions_in_humongous); i++) {
HeapRegion* const r = _g1h->region_at(i);
size_t const words_to_add = MIN2(HeapRegion::GrainWords, marked_words);
size_t const bytes_to_add = MIN2(HeapRegion::GrainBytes, marked_bytes);
log_trace(gc, marking)("Adding " SIZE_FORMAT " words to humongous region %u (%s)",
words_to_add, i, r->get_type_str());
add_marked_bytes_and_note_end(r, words_to_add * HeapWordSize);
marked_words -= words_to_add;
log_trace(gc, marking)("Adding %zu bytes to humongous region %u (%s)",
bytes_to_add, i, r->get_type_str());
add_marked_bytes_and_note_end(r, bytes_to_add);
marked_bytes -= bytes_to_add;
}
assert(marked_words == 0,
SIZE_FORMAT " words left after distributing space across %u regions",
marked_words, num_regions_in_humongous);
assert(marked_bytes == 0,
"%zu bytes left after distributing space across %u regions",
marked_bytes, num_regions_in_humongous);
}
void update_marked_bytes(HeapRegion* hr) {
uint const region_idx = hr->hrm_index();
size_t const marked_words = _cm->live_words(region_idx);
size_t const marked_bytes = _cm->live_bytes(region_idx);
// The marking attributes the object's size completely to the humongous starts
// region. We need to distribute this value across the entire set of regions a
// humongous object spans.
if (hr->is_humongous()) {
assert(hr->is_starts_humongous() || marked_words == 0,
"Should not have marked words " SIZE_FORMAT " in non-starts humongous region %u (%s)",
marked_words, region_idx, hr->get_type_str());
assert(hr->is_starts_humongous() || marked_bytes == 0,
"Should not have live bytes %zu in continues humongous region %u (%s)",
marked_bytes, region_idx, hr->get_type_str());
if (hr->is_starts_humongous()) {
distribute_marked_bytes(hr, marked_words);
distribute_marked_bytes(hr, marked_bytes);
}
} else {
log_trace(gc, marking)("Adding " SIZE_FORMAT " words to region %u (%s)", marked_words, region_idx, hr->get_type_str());
add_marked_bytes_and_note_end(hr, _cm->live_bytes(region_idx));
log_trace(gc, marking)("Adding %zu bytes to region %u (%s)", marked_bytes, region_idx, hr->get_type_str());
add_marked_bytes_and_note_end(hr, marked_bytes);
}
}

10
src/hotspot/share/gc/g1/g1ConcurrentMark.hpp
View File

@ -468,11 +468,11 @@ public:
// To be called when an object is marked the first time, e.g. after a successful
// mark_in_bitmap call. Updates various statistics data.
void add_to_liveness(uint worker_id, oop const obj, size_t size);
// Live words in the given region as determined by concurrent marking, i.e. the amount of
// live words between bottom and TAMS.
size_t live_words(uint region) const { return _region_mark_stats[region]._live_words; }
// Returns the liveness value in bytes.
size_t live_bytes(uint region) const { return live_words(region) * HeapWordSize; }
// Did the last marking find a live object between bottom and TAMS?
bool contains_live_object(uint region) const { return _region_mark_stats[region]._live_words != 0; }
// Live bytes in the given region as determined by concurrent marking, i.e. the amount of
// live bytes between bottom and TAMS.
size_t live_bytes(uint region) const { return _region_mark_stats[region]._live_words * HeapWordSize; }
// Sets the internal top_at_region_start for the given region to current top of the region.
inline void update_top_at_rebuild_start(HeapRegion* r);