Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright 2006-2007 Sun Microsystems, Inc.  All Rights Reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  *

  */

 /*

  *    The NUMA-aware allocator (MutableNUMASpace) is basically a modification

  * of MutableSpace which preserves interfaces but implements different

  * functionality. The space is split into chunks for each locality group

  * (resizing for adaptive size policy is also supported). For each thread

  * allocations are performed in the chunk corresponding to the home locality

  * group of the thread. Whenever any chunk fills-in the young generation

  * collection occurs.

  *   The chunks can be also be adaptively resized. The idea behind the adaptive

  * sizing is to reduce the loss of the space in the eden due to fragmentation.

  * The main cause of fragmentation is uneven allocation rates of threads.

  * The allocation rate difference between locality groups may be caused either by

  * application specifics or by uneven LWP distribution by the OS. Besides,

  * application can have less threads then the number of locality groups.

  * In order to resize the chunk we measure the allocation rate of the

  * application between collections. After that we reshape the chunks to reflect

  * the allocation rate pattern. The AdaptiveWeightedAverage exponentially

  * decaying average is used to smooth the measurements. The NUMASpaceResizeRate

  * parameter is used to control the adaptation speed by restricting the number of

  * bytes that can be moved during the adaptation phase.

  *   Chunks may contain pages from a wrong locality group. The page-scanner has

  * been introduced to address the problem. Remote pages typically appear due to

  * the memory shortage in the target locality group. Besides Solaris would

  * allocate a large page from the remote locality group even if there are small

  * local pages available. The page-scanner scans the pages right after the

  * collection and frees remote pages in hope that subsequent reallocation would

  * be more successful. This approach proved to be useful on systems with high

  * load where multiple processes are competing for the memory.

  */

 class MutableNUMASpace : public MutableSpace {

   friend class VMStructs;

   class LGRPSpace : public CHeapObj {

     int _lgrp_id;

     MutableSpace* _space;

     MemRegion _invalid_region;

     AdaptiveWeightedAverage *_alloc_rate;

     struct SpaceStats {

       size_t _local_space, _remote_space, _unbiased_space, _uncommited_space;

       size_t _large_pages, _small_pages;

       SpaceStats() {

         _local_space = 0;

         _remote_space = 0;

         _unbiased_space = 0;

         _uncommited_space = 0;

         _large_pages = 0;

         _small_pages = 0;

       }

     };

     SpaceStats _space_stats;

     char* _last_page_scanned;

     char* last_page_scanned()            { return _last_page_scanned; }

     void set_last_page_scanned(char* p)  { _last_page_scanned = p;    }

    public:

     LGRPSpace(int l) : _lgrp_id(l), _last_page_scanned(NULL) {

       _space = new MutableSpace();

       _alloc_rate = new AdaptiveWeightedAverage(NUMAChunkResizeWeight);

     }

     ~LGRPSpace() {

       delete _space;

       delete _alloc_rate;

     }

     void add_invalid_region(MemRegion r) {

       if (!_invalid_region.is_empty()) {

       _invalid_region.set_start(MIN2(_invalid_region.start(), r.start()));

       _invalid_region.set_end(MAX2(_invalid_region.end(), r.end()));

       } else {

       _invalid_region = r;

       }

     }

     static bool equals(void* lgrp_id_value, LGRPSpace* p) {

       return *(int*)lgrp_id_value == p->lgrp_id();

     }

     void sample() {

       alloc_rate()->sample(space()->used_in_bytes());

     }

     MemRegion invalid_region() const                { return _invalid_region;      }

     void set_invalid_region(MemRegion r)            { _invalid_region = r;         }

     int lgrp_id() const                             { return _lgrp_id;             }

     MutableSpace* space() const                     { return _space;               }

     AdaptiveWeightedAverage* alloc_rate() const     { return _alloc_rate;          }

     SpaceStats* space_stats()                       { return &_space_stats;        }

     void clear_space_stats()                        { _space_stats = SpaceStats(); }

     void accumulate_statistics(size_t page_size);

     void scan_pages(size_t page_size, size_t page_count);

   };

   GrowableArray<LGRPSpace*>* _lgrp_spaces;

   size_t _page_size;

   unsigned _adaptation_cycles, _samples_count;

   void set_page_size(size_t psz)                     { _page_size = psz;          }

   size_t page_size() const                           { return _page_size;         }

   unsigned adaptation_cycles()                       { return _adaptation_cycles; }

   void set_adaptation_cycles(int v)                  { _adaptation_cycles = v;    }

   unsigned samples_count()                           { return _samples_count;     }

   void increment_samples_count()                     { ++_samples_count;          }

   size_t _base_space_size;

   void set_base_space_size(size_t v)                 { _base_space_size = v;      }

   size_t base_space_size() const                     { return _base_space_size;   }

   // Check if the NUMA topology has changed. Add and remove spaces if needed.

   // The update can be forced by setting the force parameter equal to true.

   bool update_layout(bool force);

   // Bias region towards the lgrp.

   void bias_region(MemRegion mr, int lgrp_id);

   // Free pages in a given region.

   void free_region(MemRegion mr);

   // Get current chunk size.

   size_t current_chunk_size(int i);

   // Get default chunk size (equally divide the space).

   size_t default_chunk_size();

   // Adapt the chunk size to follow the allocation rate.

   size_t adaptive_chunk_size(int i, size_t limit);

   // Scan and free invalid pages.

   void scan_pages(size_t page_count);

   // Return the bottom_region and the top_region. Align them to page_size() boundary.

   // |------------------new_region---------------------------------|

   // |----bottom_region--|---intersection---|------top_region------|

   void select_tails(MemRegion new_region, MemRegion intersection,

                     MemRegion* bottom_region, MemRegion *top_region);

   // Try to merge the invalid region with the bottom or top region by decreasing

   // the intersection area. Return the invalid_region aligned to the page_size()

   // boundary if it's inside the intersection. Return non-empty invalid_region

   // if it lies inside the intersection (also page-aligned).

   // |------------------new_region---------------------------------|

   // |----------------|-------invalid---|--------------------------|

   // |----bottom_region--|---intersection---|------top_region------|

   void merge_regions(MemRegion new_region, MemRegion* intersection,

                      MemRegion *invalid_region);

  public:

   GrowableArray<LGRPSpace*>* lgrp_spaces() const     { return _lgrp_spaces;       }

   MutableNUMASpace();

   virtual ~MutableNUMASpace();

   // Space initialization.

   virtual void initialize(MemRegion mr, bool clear_space);

   // Update space layout if necessary. Do all adaptive resizing job.

   virtual void update();

   // Update allocation rate averages.

   virtual void accumulate_statistics();

   virtual void clear();

   virtual void mangle_unused_area();

   virtual void ensure_parsability();

   virtual size_t used_in_words() const;

   virtual size_t free_in_words() const;

   virtual size_t tlab_capacity(Thread* thr) const;

   virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;

   // Allocation (return NULL if full)

   virtual HeapWord* allocate(size_t word_size);

   virtual HeapWord* cas_allocate(size_t word_size);

   // Debugging

   virtual void print_on(outputStream* st) const;

   virtual void print_short_on(outputStream* st) const;

   virtual void verify(bool allow_dirty);

   virtual void set_top(HeapWord* value);

 };