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8155230: Tune thread usage for mark bitmap clear

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Reviewed-by: jmasa, mgerdin
This commit is contained in:
Thomas Schatzl 2016-05-02 10:24:41 +02:00
parent bd8bbf9e27
commit 72977f4009
1 changed files with 16 additions and 5 deletions
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21
hotspot/src/share/vm/gc/g1/g1ConcurrentMark.cpp
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@ -609,6 +609,10 @@ G1ConcurrentMark::~G1ConcurrentMark() {
}
class G1ClearBitMapTask : public AbstractGangTask {
public:
static size_t chunk_size() { return M; }
private:
// Heap region closure used for clearing the given mark bitmap.
class G1ClearBitmapHRClosure : public HeapRegionClosure {
private:
@ -619,7 +623,7 @@ class G1ClearBitMapTask : public AbstractGangTask {
}
virtual bool doHeapRegion(HeapRegion* r) {
size_t const chunk_size_in_words = M / HeapWordSize;
size_t const chunk_size_in_words = G1ClearBitMapTask::chunk_size() / HeapWordSize;
HeapWord* cur = r->bottom();
HeapWord* const end = r->end();
@ -653,7 +657,7 @@ class G1ClearBitMapTask : public AbstractGangTask {
public:
G1ClearBitMapTask(G1CMBitMap* bitmap, G1ConcurrentMark* cm, uint n_workers, bool suspendible) :
AbstractGangTask("Parallel Clear Bitmap Task"),
AbstractGangTask("G1 Clear Bitmap"),
_cl(bitmap, suspendible ? cm : NULL),
_hr_claimer(n_workers),
_suspendible(suspendible)
@ -672,9 +676,16 @@ public:
void G1ConcurrentMark::clear_bitmap(G1CMBitMap* bitmap, WorkGang* workers, bool may_yield) {
assert(may_yield || SafepointSynchronize::is_at_safepoint(), "Non-yielding bitmap clear only allowed at safepoint.");
G1ClearBitMapTask task(bitmap, this, workers->active_workers(), may_yield);
workers->run_task(&task);
guarantee(!may_yield || task.is_complete(), "Must have completed iteration when not yielding.");
size_t const num_bytes_to_clear = (HeapRegion::GrainBytes * _g1h->num_regions()) / G1CMBitMap::heap_map_factor();
size_t const num_chunks = align_size_up(num_bytes_to_clear, G1ClearBitMapTask::chunk_size()) / G1ClearBitMapTask::chunk_size();
uint const num_workers = (uint)MIN2(num_chunks, (size_t)workers->active_workers());
G1ClearBitMapTask cl(bitmap, this, num_workers, may_yield);
log_debug(gc, ergo)("Running %s with %u workers for " SIZE_FORMAT " work units.", cl.name(), num_workers, num_chunks);
workers->run_task(&cl, num_workers);
guarantee(!may_yield || cl.is_complete(), "Must have completed iteration when not yielding.");
}
void G1ConcurrentMark::cleanup_for_next_mark() {