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6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads

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Select number of GC threads dynamically based on heap usage and number of Java threads

Reviewed-by: johnc, ysr, jcoomes
This commit is contained in:
Jon Masamitsu 2011-08-09 10:16:01 -07:00
parent 098ed89645
commit 15070123fa
39 changed files with 1523 additions and 231 deletions
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76
hotspot/src/share/vm/gc_implementation/parallelScavenge/pcTasks.cpp
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@ -152,15 +152,16 @@ void RefProcTaskExecutor::execute(ProcessTask& task)
{
ParallelScavengeHeap* heap = PSParallelCompact::gc_heap();
uint parallel_gc_threads = heap->gc_task_manager()->workers();
uint active_gc_threads = heap->gc_task_manager()->active_workers();
RegionTaskQueueSet* qset = ParCompactionManager::region_array();
ParallelTaskTerminator terminator(parallel_gc_threads, qset);
ParallelTaskTerminator terminator(active_gc_threads, qset);
GCTaskQueue* q = GCTaskQueue::create();
for(uint i=0; i<parallel_gc_threads; i++) {
q->enqueue(new RefProcTaskProxy(task, i));
}
if (task.marks_oops_alive()) {
if (parallel_gc_threads>1) {
for (uint j=0; j<parallel_gc_threads; j++) {
for (uint j=0; j<active_gc_threads; j++) {
q->enqueue(new StealMarkingTask(&terminator));
}
}
@ -216,7 +217,6 @@ void StealMarkingTask::do_it(GCTaskManager* manager, uint which) {
// StealRegionCompactionTask
//
StealRegionCompactionTask::StealRegionCompactionTask(ParallelTaskTerminator* t):
_terminator(t) {}
@ -229,6 +229,32 @@ void StealRegionCompactionTask::do_it(GCTaskManager* manager, uint which) {
ParCompactionManager* cm =
ParCompactionManager::gc_thread_compaction_manager(which);
// If not all threads are active, get a draining stack
// from the list. Else, just use this threads draining stack.
uint which_stack_index;
bool use_all_workers = manager->all_workers_active();
if (use_all_workers) {
which_stack_index = which;
assert(manager->active_workers() == ParallelGCThreads,
err_msg("all_workers_active has been incorrectly set: "
" active %d ParallelGCThreads %d", manager->active_workers(),
ParallelGCThreads));
} else {
which_stack_index = ParCompactionManager::pop_recycled_stack_index();
}
cm->set_region_stack_index(which_stack_index);
cm->set_region_stack(ParCompactionManager::region_list(which_stack_index));
if (TraceDynamicGCThreads) {
gclog_or_tty->print_cr("StealRegionCompactionTask::do_it "
"region_stack_index %d region_stack = 0x%x "
" empty (%d) use all workers %d",
which_stack_index, ParCompactionManager::region_list(which_stack_index),
cm->region_stack()->is_empty(),
use_all_workers);
}
// Has to drain stacks first because there may be regions on
// preloaded onto the stack and this thread may never have
// done a draining task. Are the draining tasks needed?
@ -285,6 +311,50 @@ void DrainStacksCompactionTask::do_it(GCTaskManager* manager, uint which) {
ParCompactionManager* cm =
ParCompactionManager::gc_thread_compaction_manager(which);
uint which_stack_index;
bool use_all_workers = manager->all_workers_active();
if (use_all_workers) {
which_stack_index = which;
assert(manager->active_workers() == ParallelGCThreads,
err_msg("all_workers_active has been incorrectly set: "
" active %d ParallelGCThreads %d", manager->active_workers(),
ParallelGCThreads));
} else {
which_stack_index = stack_index();
}
cm->set_region_stack(ParCompactionManager::region_list(which_stack_index));
if (TraceDynamicGCThreads) {
gclog_or_tty->print_cr("DrainStacksCompactionTask::do_it which = %d "
"which_stack_index = %d/empty(%d) "
"use all workers %d",
which, which_stack_index,
cm->region_stack()->is_empty(),
use_all_workers);
}
cm->set_region_stack_index(which_stack_index);
// Process any regions already in the compaction managers stacks.
cm->drain_region_stacks();
assert(cm->region_stack()->is_empty(), "Not empty");
if (!use_all_workers) {
// Always give up the region stack.
assert(cm->region_stack() ==
ParCompactionManager::region_list(cm->region_stack_index()),
"region_stack and region_stack_index are inconsistent");
ParCompactionManager::push_recycled_stack_index(cm->region_stack_index());
if (TraceDynamicGCThreads) {
void* old_region_stack = (void*) cm->region_stack();
int old_region_stack_index = cm->region_stack_index();
gclog_or_tty->print_cr("Pushing region stack 0x%x/%d",
old_region_stack, old_region_stack_index);
}
cm->set_region_stack(NULL);
cm->set_region_stack_index((uint)max_uintx);
}
}