jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/shared/mutableSpace.cpp@b2ef234911c9 (annotated)

src/share/vm/gc_implementation/shared/mutableSpace.cpp@b2ef234911c9 (annotated)

src/share/vm/gc_implementation/shared/mutableSpace.cpp

Thu, 20 Sep 2012 09:52:56 -0700

author: johnc
date: Thu, 20 Sep 2012 09:52:56 -0700
changeset 4067: b2ef234911c9
parent 4037: da91efe96a93
child 4542: db9981fd3124
permissions: -rw-r--r--

7190666: G1: assert(_unused == 0) failed: Inconsistency in PLAB stats
Summary: Reset the fields in ParGCAllocBuffer, that are used for accumulating values for the ResizePLAB sensors in PLABStats, to zero after flushing the values to the PLABStats fields. Flush PLABStats values only when retiring the final allocation buffers prior to disposing of a G1ParScanThreadState object, rather than when retiring every allocation buffer.
Reviewed-by: jwilhelm, jmasa, ysr

 /*
  * Copyright (c) 2001, 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #ifndef SERIALGC
 #include "gc_implementation/shared/mutableSpace.hpp"
 #include "gc_implementation/shared/spaceDecorator.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/safepoint.hpp"
 #include "runtime/thread.hpp"
 #endif
 MutableSpace::MutableSpace(size_t alignment): ImmutableSpace(), _top(NULL), _alignment(alignment) {
   assert(MutableSpace::alignment() >= 0 &&
          MutableSpace::alignment() % os::vm_page_size() == 0,
          "Space should be aligned");
   _mangler = new MutableSpaceMangler(this);
 }
 MutableSpace::~MutableSpace() {
   delete _mangler;
 }
 void MutableSpace::numa_setup_pages(MemRegion mr, bool clear_space) {
   if (!mr.is_empty()) {
     size_t page_size = UseLargePages ? alignment() : os::vm_page_size();
     HeapWord *start = (HeapWord*)round_to((intptr_t) mr.start(), page_size);
     HeapWord *end =  (HeapWord*)round_down((intptr_t) mr.end(), page_size);
     if (end > start) {
       size_t size = pointer_delta(end, start, sizeof(char));
       if (clear_space) {
         // Prefer page reallocation to migration.
         os::free_memory((char*)start, size, page_size);
       }
       os::numa_make_global((char*)start, size);
     }
   }
 }
 void MutableSpace::pretouch_pages(MemRegion mr) {
   for (volatile char *p = (char*)mr.start(); p < (char*)mr.end(); p += os::vm_page_size()) {
     char t = *p; *p = t;
   }
 }
 void MutableSpace::initialize(MemRegion mr,
                               bool clear_space,
                               bool mangle_space,
                               bool setup_pages) {
   assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
          "invalid space boundaries");
   if (setup_pages && (UseNUMA || AlwaysPreTouch)) {
     // The space may move left and right or expand/shrink.
     // We'd like to enforce the desired page placement.
     MemRegion head, tail;
     if (last_setup_region().is_empty()) {
       // If it's the first initialization don't limit the amount of work.
       head = mr;
       tail = MemRegion(mr.end(), mr.end());
     } else {
       // Is there an intersection with the address space?
       MemRegion intersection = last_setup_region().intersection(mr);
       if (intersection.is_empty()) {
         intersection = MemRegion(mr.end(), mr.end());
       }
       // All the sizes below are in words.
       size_t head_size = 0, tail_size = 0;
       if (mr.start() <= intersection.start()) {
         head_size = pointer_delta(intersection.start(), mr.start());
       }
       if(intersection.end() <= mr.end()) {
         tail_size = pointer_delta(mr.end(), intersection.end());
       }
       // Limit the amount of page manipulation if necessary.
       if (NUMASpaceResizeRate > 0 && !AlwaysPreTouch) {
         const size_t change_size = head_size + tail_size;
         const float setup_rate_words = NUMASpaceResizeRate >> LogBytesPerWord;
         head_size = MIN2((size_t)(setup_rate_words * head_size / change_size),
                          head_size);
         tail_size = MIN2((size_t)(setup_rate_words * tail_size / change_size),
                          tail_size);
       }
       head = MemRegion(intersection.start() - head_size, intersection.start());
       tail = MemRegion(intersection.end(), intersection.end() + tail_size);
     }
     assert(mr.contains(head) && mr.contains(tail), "Sanity");
     if (UseNUMA) {
       numa_setup_pages(head, clear_space);
       numa_setup_pages(tail, clear_space);
     }
     if (AlwaysPreTouch) {
       pretouch_pages(head);
       pretouch_pages(tail);
     }
     // Remember where we stopped so that we can continue later.
     set_last_setup_region(MemRegion(head.start(), tail.end()));
   }
   set_bottom(mr.start());
   set_end(mr.end());
   if (clear_space) {
     clear(mangle_space);
   }
 }
 void MutableSpace::clear(bool mangle_space) {
   set_top(bottom());
   if (ZapUnusedHeapArea && mangle_space) {
     mangle_unused_area();
   }
 }
 #ifndef PRODUCT
 void MutableSpace::check_mangled_unused_area(HeapWord* limit) {
   mangler()->check_mangled_unused_area(limit);
 }
 void MutableSpace::check_mangled_unused_area_complete() {
   mangler()->check_mangled_unused_area_complete();
 }
 // Mangle only the unused space that has not previously
 // been mangled and that has not been allocated since being
 // mangled.
 void MutableSpace::mangle_unused_area() {
   mangler()->mangle_unused_area();
 }
 void MutableSpace::mangle_unused_area_complete() {
   mangler()->mangle_unused_area_complete();
 }
 void MutableSpace::mangle_region(MemRegion mr) {
   SpaceMangler::mangle_region(mr);
 }
 void MutableSpace::set_top_for_allocations(HeapWord* v) {
   mangler()->set_top_for_allocations(v);
 }
 void MutableSpace::set_top_for_allocations() {
   mangler()->set_top_for_allocations(top());
 }
 #endif
 // This version requires locking. */
 HeapWord* MutableSpace::allocate(size_t size) {
   assert(Heap_lock->owned_by_self() ||
          (SafepointSynchronize::is_at_safepoint() &&
           Thread::current()->is_VM_thread()),
          "not locked");
   HeapWord* obj = top();
   if (pointer_delta(end(), obj) >= size) {
     HeapWord* new_top = obj + size;
     set_top(new_top);
     assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
            "checking alignment");
     return obj;
   } else {
     return NULL;
   }
 }
 // This version is lock-free.
 HeapWord* MutableSpace::cas_allocate(size_t size) {
   do {
     HeapWord* obj = top();
     if (pointer_delta(end(), obj) >= size) {
       HeapWord* new_top = obj + size;
       HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
       // result can be one of two:
       //  the old top value: the exchange succeeded
       //  otherwise: the new value of the top is returned.
       if (result != obj) {
         continue; // another thread beat us to the allocation, try again
       }
       assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
              "checking alignment");
       return obj;
     } else {
       return NULL;
     }
   } while (true);
 }
 // Try to deallocate previous allocation. Returns true upon success.
 bool MutableSpace::cas_deallocate(HeapWord *obj, size_t size) {
   HeapWord* expected_top = obj + size;
   return (HeapWord*)Atomic::cmpxchg_ptr(obj, top_addr(), expected_top) == expected_top;
 }
 void MutableSpace::oop_iterate(ExtendedOopClosure* cl) {
   HeapWord* obj_addr = bottom();
   HeapWord* t = top();
   // Could call objects iterate, but this is easier.
   while (obj_addr < t) {
     obj_addr += oop(obj_addr)->oop_iterate(cl);
   }
 }
 void MutableSpace::oop_iterate_no_header(OopClosure* cl) {
   HeapWord* obj_addr = bottom();
   HeapWord* t = top();
   // Could call objects iterate, but this is easier.
   while (obj_addr < t) {
     obj_addr += oop(obj_addr)->oop_iterate_no_header(cl);
   }
 }
 void MutableSpace::object_iterate(ObjectClosure* cl) {
   HeapWord* p = bottom();
   while (p < top()) {
     cl->do_object(oop(p));
     p += oop(p)->size();
   }
 }
 void MutableSpace::print_short() const { print_short_on(tty); }
 void MutableSpace::print_short_on( outputStream* st) const {
   st->print(" space " SIZE_FORMAT "K, %d%% used", capacity_in_bytes() / K,
             (int) ((double) used_in_bytes() * 100 / capacity_in_bytes()));
 }
 void MutableSpace::print() const { print_on(tty); }
 void MutableSpace::print_on(outputStream* st) const {
   MutableSpace::print_short_on(st);
   st->print_cr(" [" INTPTR_FORMAT "," INTPTR_FORMAT "," INTPTR_FORMAT ")",
                  bottom(), top(), end());
 }
 void MutableSpace::verify() {
   HeapWord* p = bottom();
   HeapWord* t = top();
   HeapWord* prev_p = NULL;
   while (p < t) {
     oop(p)->verify();
     prev_p = p;
     p += oop(p)->size();
   }
   guarantee(p == top(), "end of last object must match end of space");
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/shared/mutableSpace.cpp@b2ef234911c9 (annotated)

src/share/vm/gc_implementation/shared/mutableSpace.cpp