src/share/vm/memory/threadLocalAllocBuffer.hpp

Wed, 07 Apr 2010 12:39:27 -0700

author
kvn
date
Wed, 07 Apr 2010 12:39:27 -0700
changeset 1802
9e321dcfa5b7
parent 435
a61af66fc99e
child 1907
c18cbe5936b8
permissions
-rw-r--r--

6940726: Use BIS instruction for allocation prefetch on Sparc
Summary: Use BIS instruction for allocation prefetch on Sparc
Reviewed-by: twisti

     1 /*
     2  * Copyright 1999-2007 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 class GlobalTLABStats;
    27 // ThreadLocalAllocBuffer: a descriptor for thread-local storage used by
    28 // the threads for allocation.
    29 //            It is thread-private at any time, but maybe multiplexed over
    30 //            time across multiple threads. The park()/unpark() pair is
    31 //            used to make it avaiable for such multiplexing.
    32 class ThreadLocalAllocBuffer: public CHeapObj {
    33   friend class VMStructs;
    34 private:
    35   HeapWord* _start;                              // address of TLAB
    36   HeapWord* _top;                                // address after last allocation
    37   HeapWord* _pf_top;                             // allocation prefetch watermark
    38   HeapWord* _end;                                // allocation end (excluding alignment_reserve)
    39   size_t    _desired_size;                       // desired size   (including alignment_reserve)
    40   size_t    _refill_waste_limit;                 // hold onto tlab if free() is larger than this
    42   static unsigned _target_refills;               // expected number of refills between GCs
    44   unsigned  _number_of_refills;
    45   unsigned  _fast_refill_waste;
    46   unsigned  _slow_refill_waste;
    47   unsigned  _gc_waste;
    48   unsigned  _slow_allocations;
    50   AdaptiveWeightedAverage _allocation_fraction;  // fraction of eden allocated in tlabs
    52   void accumulate_statistics();
    53   void initialize_statistics();
    55   void set_start(HeapWord* start)                { _start = start; }
    56   void set_end(HeapWord* end)                    { _end = end; }
    57   void set_top(HeapWord* top)                    { _top = top; }
    58   void set_pf_top(HeapWord* pf_top)              { _pf_top = pf_top; }
    59   void set_desired_size(size_t desired_size)     { _desired_size = desired_size; }
    60   void set_refill_waste_limit(size_t waste)      { _refill_waste_limit = waste;  }
    62   size_t initial_refill_waste_limit()            { return desired_size() / TLABRefillWasteFraction; }
    64   static int    target_refills()                 { return _target_refills; }
    65   size_t initial_desired_size();
    67   size_t remaining() const                       { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
    69   // Make parsable and release it.
    70   void reset();
    72   // Resize based on amount of allocation, etc.
    73   void resize();
    75   void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
    77   void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
    79   void print_stats(const char* tag);
    81   Thread* myThread();
    83   // statistics
    85   int number_of_refills() const { return _number_of_refills; }
    86   int fast_refill_waste() const { return _fast_refill_waste; }
    87   int slow_refill_waste() const { return _slow_refill_waste; }
    88   int gc_waste() const          { return _gc_waste; }
    89   int slow_allocations() const  { return _slow_allocations; }
    91   static GlobalTLABStats* _global_stats;
    92   static GlobalTLABStats* global_stats() { return _global_stats; }
    94 public:
    95   ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight) {
    96     // do nothing.  tlabs must be inited by initialize() calls
    97   }
    99   static const size_t min_size()                 { return align_object_size(MinTLABSize / HeapWordSize); }
   100   static const size_t max_size();
   102   HeapWord* start() const                        { return _start; }
   103   HeapWord* end() const                          { return _end; }
   104   HeapWord* hard_end() const                     { return _end + alignment_reserve(); }
   105   HeapWord* top() const                          { return _top; }
   106   HeapWord* pf_top() const                       { return _pf_top; }
   107   size_t desired_size() const                    { return _desired_size; }
   108   size_t free() const                            { return pointer_delta(end(), top()); }
   109   // Don't discard tlab if remaining space is larger than this.
   110   size_t refill_waste_limit() const              { return _refill_waste_limit; }
   112   // Allocate size HeapWords. The memory is NOT initialized to zero.
   113   inline HeapWord* allocate(size_t size);
   115   // Reserve space at the end of TLAB
   116   static size_t end_reserve() {
   117     int reserve_size = typeArrayOopDesc::header_size(T_INT);
   118     if (AllocatePrefetchStyle == 3) {
   119       // BIS is used to prefetch - we need a space for it.
   120       // +1 for rounding up to next cache line +1 to be safe
   121       int lines = AllocatePrefetchLines + 2;
   122       int step_size = AllocatePrefetchStepSize;
   123       int distance = AllocatePrefetchDistance;
   124       int prefetch_end = (distance + step_size*lines)/(int)HeapWordSize;
   125       reserve_size = MAX2(reserve_size, prefetch_end);
   126     }
   127     return reserve_size;
   128   }
   129   static size_t alignment_reserve()              { return align_object_size(end_reserve()); }
   130   static size_t alignment_reserve_in_bytes()     { return alignment_reserve() * HeapWordSize; }
   132   // Return tlab size or remaining space in eden such that the
   133   // space is large enough to hold obj_size and necessary fill space.
   134   // Otherwise return 0;
   135   inline size_t compute_size(size_t obj_size);
   137   // Record slow allocation
   138   inline void record_slow_allocation(size_t obj_size);
   140   // Initialization at startup
   141   static void startup_initialization();
   143   // Make an in-use tlab parsable, optionally also retiring it.
   144   void make_parsable(bool retire);
   146   // Retire in-use tlab before allocation of a new tlab
   147   void clear_before_allocation();
   149   // Accumulate statistics across all tlabs before gc
   150   static void accumulate_statistics_before_gc();
   152   // Resize tlabs for all threads
   153   static void resize_all_tlabs();
   155   void fill(HeapWord* start, HeapWord* top, size_t new_size);
   156   void initialize();
   158   static size_t refill_waste_limit_increment()   { return TLABWasteIncrement; }
   160   // Code generation support
   161   static ByteSize start_offset()                 { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
   162   static ByteSize end_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _end  ); }
   163   static ByteSize top_offset()                   { return byte_offset_of(ThreadLocalAllocBuffer, _top  ); }
   164   static ByteSize pf_top_offset()                { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top  ); }
   165   static ByteSize size_offset()                  { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
   166   static ByteSize refill_waste_limit_offset()    { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
   168   static ByteSize number_of_refills_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
   169   static ByteSize fast_refill_waste_offset()     { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
   170   static ByteSize slow_allocations_offset()      { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); }
   172   void verify();
   173 };
   175 class GlobalTLABStats: public CHeapObj {
   176 private:
   178   // Accumulate perfdata in private variables because
   179   // PerfData should be write-only for security reasons
   180   // (see perfData.hpp)
   181   unsigned _allocating_threads;
   182   unsigned _total_refills;
   183   unsigned _max_refills;
   184   size_t   _total_allocation;
   185   size_t   _total_gc_waste;
   186   size_t   _max_gc_waste;
   187   size_t   _total_slow_refill_waste;
   188   size_t   _max_slow_refill_waste;
   189   size_t   _total_fast_refill_waste;
   190   size_t   _max_fast_refill_waste;
   191   unsigned _total_slow_allocations;
   192   unsigned _max_slow_allocations;
   194   PerfVariable* _perf_allocating_threads;
   195   PerfVariable* _perf_total_refills;
   196   PerfVariable* _perf_max_refills;
   197   PerfVariable* _perf_allocation;
   198   PerfVariable* _perf_gc_waste;
   199   PerfVariable* _perf_max_gc_waste;
   200   PerfVariable* _perf_slow_refill_waste;
   201   PerfVariable* _perf_max_slow_refill_waste;
   202   PerfVariable* _perf_fast_refill_waste;
   203   PerfVariable* _perf_max_fast_refill_waste;
   204   PerfVariable* _perf_slow_allocations;
   205   PerfVariable* _perf_max_slow_allocations;
   207   AdaptiveWeightedAverage _allocating_threads_avg;
   209 public:
   210   GlobalTLABStats();
   212   // Initialize all counters
   213   void initialize();
   215   // Write all perf counters to the perf_counters
   216   void publish();
   218   void print();
   220   // Accessors
   221   unsigned allocating_threads_avg() {
   222     return MAX2((unsigned)(_allocating_threads_avg.average() + 0.5), 1U);
   223   }
   225   size_t allocation() {
   226     return _total_allocation;
   227   }
   229   // Update methods
   231   void update_allocating_threads() {
   232     _allocating_threads++;
   233   }
   234   void update_number_of_refills(unsigned value) {
   235     _total_refills += value;
   236     _max_refills    = MAX2(_max_refills, value);
   237   }
   238   void update_allocation(size_t value) {
   239     _total_allocation += value;
   240   }
   241   void update_gc_waste(size_t value) {
   242     _total_gc_waste += value;
   243     _max_gc_waste    = MAX2(_max_gc_waste, value);
   244   }
   245   void update_fast_refill_waste(size_t value) {
   246     _total_fast_refill_waste += value;
   247     _max_fast_refill_waste    = MAX2(_max_fast_refill_waste, value);
   248   }
   249   void update_slow_refill_waste(size_t value) {
   250     _total_slow_refill_waste += value;
   251     _max_slow_refill_waste    = MAX2(_max_slow_refill_waste, value);
   252   }
   253   void update_slow_allocations(unsigned value) {
   254     _total_slow_allocations += value;
   255     _max_slow_allocations    = MAX2(_max_slow_allocations, value);
   256   }
   257 };

mercurial