Mercurial > hg > truffle
diff src/share/vm/gc_implementation/parallelScavenge/pcTasks.cpp @ 4095:bca17e38de00
6593758: RFE: Enhance GC ergonomics to dynamically choose ParallelGCThreads
Summary: Select number of GC threads dynamically based on heap usage and number of Java threads
Reviewed-by: johnc, ysr, jcoomes
author | jmasa |
---|---|
date | Tue, 09 Aug 2011 10:16:01 -0700 |
parents | c2bf0120ee5d |
children | da91efe96a93 |
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--- a/src/share/vm/gc_implementation/parallelScavenge/pcTasks.cpp Tue Nov 22 04:47:10 2011 -0500 +++ b/src/share/vm/gc_implementation/parallelScavenge/pcTasks.cpp Tue Aug 09 10:16:01 2011 -0700 @@ -152,15 +152,16 @@ { 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 @@ // StealRegionCompactionTask // - StealRegionCompactionTask::StealRegionCompactionTask(ParallelTaskTerminator* t): _terminator(t) {} @@ -229,6 +229,32 @@ 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 @@ 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); + } }