# HG changeset patch # User ysr # Date 1233353872 28800 # Node ID 23673011938df756add76c00750429f62672e584 # Parent 5b39c489c39dee534f37823705f8516338990bd9 6787254: Work queue capacity can be increased substantially on some platforms Summary: Increased the default and maximum size of the CMS marking stack and the size of the parallel workers' work queues in 64-bit mode. The latter was accomplished by an increase in the width of the Taskqueue's Age struct and its Tag field in 64-bit mode. Reviewed-by: jmasa, tonyp diff -r 5b39c489c39d -r 23673011938d src/share/vm/runtime/globals.hpp --- a/src/share/vm/runtime/globals.hpp Thu Jan 29 21:25:42 2009 -0800 +++ b/src/share/vm/runtime/globals.hpp Fri Jan 30 14:17:52 2009 -0800 @@ -1426,10 +1426,10 @@ develop(bool, CMSOverflowEarlyRestoration, false, \ "Whether preserved marks should be restored early") \ \ - product(uintx, CMSMarkStackSize, 32*K, \ + product(uintx, CMSMarkStackSize, NOT_LP64(32*K) LP64_ONLY(4*M), \ "Size of CMS marking stack") \ \ - product(uintx, CMSMarkStackSizeMax, 4*M, \ + product(uintx, CMSMarkStackSizeMax, NOT_LP64(4*M) LP64_ONLY(512*M), \ "Max size of CMS marking stack") \ \ notproduct(bool, CMSMarkStackOverflowALot, false, \ diff -r 5b39c489c39d -r 23673011938d src/share/vm/utilities/taskqueue.cpp --- a/src/share/vm/utilities/taskqueue.cpp Thu Jan 29 21:25:42 2009 -0800 +++ b/src/share/vm/utilities/taskqueue.cpp Fri Jan 30 14:17:52 2009 -0800 @@ -69,7 +69,7 @@ ParallelTaskTerminator::offer_termination(TerminatorTerminator* terminator) { Atomic::inc(&_offered_termination); - juint yield_count = 0; + uint yield_count = 0; while (true) { if (_offered_termination == _n_threads) { //inner_termination_loop(); diff -r 5b39c489c39d -r 23673011938d src/share/vm/utilities/taskqueue.hpp --- a/src/share/vm/utilities/taskqueue.hpp Thu Jan 29 21:25:42 2009 -0800 +++ b/src/share/vm/utilities/taskqueue.hpp Fri Jan 30 14:17:52 2009 -0800 @@ -22,67 +22,76 @@ * */ +#ifdef LP64 +typedef juint TAG_TYPE; +// for a taskqueue size of 4M +#define LOG_TASKQ_SIZE 22 +#else +typedef jushort TAG_TYPE; +// for a taskqueue size of 16K +#define LOG_TASKQ_SIZE 14 +#endif + class TaskQueueSuper: public CHeapObj { protected: // The first free element after the last one pushed (mod _n). - // (For now we'll assume only 32-bit CAS). - volatile juint _bottom; + volatile uint _bottom; // log2 of the size of the queue. enum SomeProtectedConstants { - Log_n = 14 + Log_n = LOG_TASKQ_SIZE }; +#undef LOG_TASKQ_SIZE // Size of the queue. - juint n() { return (1 << Log_n); } + uint n() { return (1 << Log_n); } // For computing "x mod n" efficiently. - juint n_mod_mask() { return n() - 1; } + uint n_mod_mask() { return n() - 1; } struct Age { - jushort _top; - jushort _tag; + TAG_TYPE _top; + TAG_TYPE _tag; - jushort tag() const { return _tag; } - jushort top() const { return _top; } + TAG_TYPE tag() const { return _tag; } + TAG_TYPE top() const { return _top; } Age() { _tag = 0; _top = 0; } friend bool operator ==(const Age& a1, const Age& a2) { return a1.tag() == a2.tag() && a1.top() == a2.top(); } - }; Age _age; // These make sure we do single atomic reads and writes. Age get_age() { - jint res = *(volatile jint*)(&_age); + uint res = *(volatile uint*)(&_age); return *(Age*)(&res); } void set_age(Age a) { - *(volatile jint*)(&_age) = *(int*)(&a); + *(volatile uint*)(&_age) = *(uint*)(&a); } - jushort get_top() { + TAG_TYPE get_top() { return get_age().top(); } // These both operate mod _n. - juint increment_index(juint ind) { + uint increment_index(uint ind) { return (ind + 1) & n_mod_mask(); } - juint decrement_index(juint ind) { + uint decrement_index(uint ind) { return (ind - 1) & n_mod_mask(); } // Returns a number in the range [0.._n). If the result is "n-1", it // should be interpreted as 0. - juint dirty_size(juint bot, juint top) { - return ((jint)bot - (jint)top) & n_mod_mask(); + uint dirty_size(uint bot, uint top) { + return ((int)bot - (int)top) & n_mod_mask(); } // Returns the size corresponding to the given "bot" and "top". - juint size(juint bot, juint top) { - juint sz = dirty_size(bot, top); + uint size(uint bot, uint top) { + uint sz = dirty_size(bot, top); // Has the queue "wrapped", so that bottom is less than top? // There's a complicated special case here. A pair of threads could // perform pop_local and pop_global operations concurrently, starting @@ -94,7 +103,7 @@ // owner performs pop_local's, and several concurrent threads // attempting to perform the pop_global will all perform the same CAS, // and only one can succeed. Any stealing thread that reads after - // either the increment or decrement will seen an empty queue, and will + // either the increment or decrement will see an empty queue, and will // not join the competitors. The "sz == -1 || sz == _n-1" state will // not be modified by concurrent queues, so the owner thread can reset // the state to _bottom == top so subsequent pushes will be performed @@ -112,11 +121,11 @@ // Return an estimate of the number of elements in the queue. // The "careful" version admits the possibility of pop_local/pop_global // races. - juint size() { + uint size() { return size(_bottom, get_top()); } - juint dirty_size() { + uint dirty_size() { return dirty_size(_bottom, get_top()); } @@ -127,15 +136,15 @@ // Maximum number of elements allowed in the queue. This is two less // than the actual queue size, for somewhat complicated reasons. - juint max_elems() { return n() - 2; } + uint max_elems() { return n() - 2; } }; template class GenericTaskQueue: public TaskQueueSuper { private: // Slow paths for push, pop_local. (pop_global has no fast path.) - bool push_slow(E t, juint dirty_n_elems); - bool pop_local_slow(juint localBot, Age oldAge); + bool push_slow(E t, uint dirty_n_elems); + bool pop_local_slow(uint localBot, Age oldAge); public: // Initializes the queue to empty. @@ -170,7 +179,7 @@ template GenericTaskQueue::GenericTaskQueue():TaskQueueSuper() { - assert(sizeof(Age) == sizeof(jint), "Depends on this."); + assert(sizeof(Age) == sizeof(int), "Depends on this."); } template @@ -182,9 +191,9 @@ template void GenericTaskQueue::oops_do(OopClosure* f) { // tty->print_cr("START OopTaskQueue::oops_do"); - int iters = size(); - juint index = _bottom; - for (int i = 0; i < iters; ++i) { + uint iters = size(); + uint index = _bottom; + for (uint i = 0; i < iters; ++i) { index = decrement_index(index); // tty->print_cr(" doing entry %d," INTPTR_T " -> " INTPTR_T, // index, &_elems[index], _elems[index]); @@ -198,10 +207,10 @@ template -bool GenericTaskQueue::push_slow(E t, juint dirty_n_elems) { +bool GenericTaskQueue::push_slow(E t, uint dirty_n_elems) { if (dirty_n_elems == n() - 1) { // Actually means 0, so do the push. - juint localBot = _bottom; + uint localBot = _bottom; _elems[localBot] = t; _bottom = increment_index(localBot); return true; @@ -211,7 +220,7 @@ template bool GenericTaskQueue:: -pop_local_slow(juint localBot, Age oldAge) { +pop_local_slow(uint localBot, Age oldAge) { // This queue was observed to contain exactly one element; either this // thread will claim it, or a competing "pop_global". In either case, // the queue will be logically empty afterwards. Create a new Age value @@ -230,9 +239,8 @@ Age tempAge; // No competing pop_global has yet incremented "top"; we'll try to // install new_age, thus claiming the element. - assert(sizeof(Age) == sizeof(jint) && sizeof(jint) == sizeof(juint), - "Assumption about CAS unit."); - *(jint*)&tempAge = Atomic::cmpxchg(*(jint*)&newAge, (volatile jint*)&_age, *(jint*)&oldAge); + assert(sizeof(Age) == sizeof(int), "Assumption about CAS unit."); + *(uint*)&tempAge = Atomic::cmpxchg(*(uint*)&newAge, (volatile uint*)&_age, *(uint*)&oldAge); if (tempAge == oldAge) { // We win. assert(dirty_size(localBot, get_top()) != n() - 1, @@ -253,8 +261,8 @@ bool GenericTaskQueue::pop_global(E& t) { Age newAge; Age oldAge = get_age(); - juint localBot = _bottom; - juint n_elems = size(localBot, oldAge.top()); + uint localBot = _bottom; + uint n_elems = size(localBot, oldAge.top()); if (n_elems == 0) { return false; } @@ -263,7 +271,7 @@ newAge._top = increment_index(newAge.top()); if ( newAge._top == 0 ) newAge._tag++; Age resAge; - *(jint*)&resAge = Atomic::cmpxchg(*(jint*)&newAge, (volatile jint*)&_age, *(jint*)&oldAge); + *(uint*)&resAge = Atomic::cmpxchg(*(uint*)&newAge, (volatile uint*)&_age, *(uint*)&oldAge); // Note that using "_bottom" here might fail, since a pop_local might // have decremented it. assert(dirty_size(localBot, newAge._top) != n() - 1, @@ -287,7 +295,7 @@ template class GenericTaskQueueSet: public TaskQueueSetSuper { private: - int _n; + uint _n; GenericTaskQueue** _queues; public: @@ -300,51 +308,51 @@ } } - bool steal_1_random(int queue_num, int* seed, E& t); - bool steal_best_of_2(int queue_num, int* seed, E& t); - bool steal_best_of_all(int queue_num, int* seed, E& t); + bool steal_1_random(uint queue_num, int* seed, E& t); + bool steal_best_of_2(uint queue_num, int* seed, E& t); + bool steal_best_of_all(uint queue_num, int* seed, E& t); - void register_queue(int i, GenericTaskQueue* q); + void register_queue(uint i, GenericTaskQueue* q); - GenericTaskQueue* queue(int n); + GenericTaskQueue* queue(uint n); // The thread with queue number "queue_num" (and whose random number seed // is at "seed") is trying to steal a task from some other queue. (It // may try several queues, according to some configuration parameter.) // If some steal succeeds, returns "true" and sets "t" the stolen task, // otherwise returns false. - bool steal(int queue_num, int* seed, E& t); + bool steal(uint queue_num, int* seed, E& t); bool peek(); }; template -void GenericTaskQueueSet::register_queue(int i, GenericTaskQueue* q) { - assert(0 <= i && i < _n, "index out of range."); +void GenericTaskQueueSet::register_queue(uint i, GenericTaskQueue* q) { + assert(i < _n, "index out of range."); _queues[i] = q; } template -GenericTaskQueue* GenericTaskQueueSet::queue(int i) { +GenericTaskQueue* GenericTaskQueueSet::queue(uint i) { return _queues[i]; } template -bool GenericTaskQueueSet::steal(int queue_num, int* seed, E& t) { - for (int i = 0; i < 2 * _n; i++) +bool GenericTaskQueueSet::steal(uint queue_num, int* seed, E& t) { + for (uint i = 0; i < 2 * _n; i++) if (steal_best_of_2(queue_num, seed, t)) return true; return false; } template -bool GenericTaskQueueSet::steal_best_of_all(int queue_num, int* seed, E& t) { +bool GenericTaskQueueSet::steal_best_of_all(uint queue_num, int* seed, E& t) { if (_n > 2) { int best_k; - jint best_sz = 0; - for (int k = 0; k < _n; k++) { + uint best_sz = 0; + for (uint k = 0; k < _n; k++) { if (k == queue_num) continue; - jint sz = _queues[k]->size(); + uint sz = _queues[k]->size(); if (sz > best_sz) { best_sz = sz; best_k = k; @@ -362,9 +370,9 @@ } template -bool GenericTaskQueueSet::steal_1_random(int queue_num, int* seed, E& t) { +bool GenericTaskQueueSet::steal_1_random(uint queue_num, int* seed, E& t) { if (_n > 2) { - int k = queue_num; + uint k = queue_num; while (k == queue_num) k = randomParkAndMiller(seed) % _n; return _queues[2]->pop_global(t); } else if (_n == 2) { @@ -378,20 +386,20 @@ } template -bool GenericTaskQueueSet::steal_best_of_2(int queue_num, int* seed, E& t) { +bool GenericTaskQueueSet::steal_best_of_2(uint queue_num, int* seed, E& t) { if (_n > 2) { - int k1 = queue_num; + uint k1 = queue_num; while (k1 == queue_num) k1 = randomParkAndMiller(seed) % _n; - int k2 = queue_num; + uint k2 = queue_num; while (k2 == queue_num || k2 == k1) k2 = randomParkAndMiller(seed) % _n; // Sample both and try the larger. - juint sz1 = _queues[k1]->size(); - juint sz2 = _queues[k2]->size(); + uint sz1 = _queues[k1]->size(); + uint sz2 = _queues[k2]->size(); if (sz2 > sz1) return _queues[k2]->pop_global(t); else return _queues[k1]->pop_global(t); } else if (_n == 2) { // Just try the other one. - int k = (queue_num + 1) % 2; + uint k = (queue_num + 1) % 2; return _queues[k]->pop_global(t); } else { assert(_n == 1, "can't be zero."); @@ -402,7 +410,7 @@ template bool GenericTaskQueueSet::peek() { // Try all the queues. - for (int j = 0; j < _n; j++) { + for (uint j = 0; j < _n; j++) { if (_queues[j]->peek()) return true; } @@ -422,7 +430,7 @@ private: int _n_threads; TaskQueueSetSuper* _queue_set; - jint _offered_termination; + int _offered_termination; bool peek_in_queue_set(); protected: @@ -460,7 +468,7 @@ template inline bool GenericTaskQueue::push(E t) { #if SIMPLE_STACK - juint localBot = _bottom; + uint localBot = _bottom; if (_bottom < max_elems()) { _elems[localBot] = t; _bottom = localBot + 1; @@ -469,10 +477,10 @@ return false; } #else - juint localBot = _bottom; + uint localBot = _bottom; assert((localBot >= 0) && (localBot < n()), "_bottom out of range."); - jushort top = get_top(); - juint dirty_n_elems = dirty_size(localBot, top); + TAG_TYPE top = get_top(); + uint dirty_n_elems = dirty_size(localBot, top); assert((dirty_n_elems >= 0) && (dirty_n_elems < n()), "n_elems out of range."); if (dirty_n_elems < max_elems()) { @@ -487,19 +495,19 @@ template inline bool GenericTaskQueue::pop_local(E& t) { #if SIMPLE_STACK - juint localBot = _bottom; + uint localBot = _bottom; assert(localBot > 0, "precondition."); localBot--; t = _elems[localBot]; _bottom = localBot; return true; #else - juint localBot = _bottom; + uint localBot = _bottom; // This value cannot be n-1. That can only occur as a result of // the assignment to bottom in this method. If it does, this method // resets the size( to 0 before the next call (which is sequential, // since this is pop_local.) - juint dirty_n_elems = dirty_size(localBot, get_top()); + uint dirty_n_elems = dirty_size(localBot, get_top()); assert(dirty_n_elems != n() - 1, "Shouldn't be possible..."); if (dirty_n_elems == 0) return false; localBot = decrement_index(localBot); @@ -512,7 +520,7 @@ // If there's still at least one element in the queue, based on the // "_bottom" and "age" we've read, then there can be no interference with // a "pop_global" operation, and we're done. - juint tp = get_top(); + TAG_TYPE tp = get_top(); // XXX if (size(localBot, tp) > 0) { assert(dirty_size(localBot, tp) != n() - 1, "Shouldn't be possible..."); @@ -581,7 +589,7 @@ bool is_empty(); bool stealable_is_empty(); bool overflow_is_empty(); - juint stealable_size() { return _region_queue.size(); } + uint stealable_size() { return _region_queue.size(); } RegionTaskQueue* task_queue() { return &_region_queue; } };