view src/share/vm/memory/threadLocalAllocBuffer.inline.hpp @ 2368:dde920245681

6896099: Integrate CMS heap ergo with default heap sizing ergo 6627787: CMS: JVM refuses to start up with -Xms16m -Xmx16m 7000125: CMS: Anti-monotone young gen sizing with respect to maximum whole heap size specification 7027529: CMS: retire CMSUseOldDefaults flag Summary: Simplify CMS heap sizing code, relying on ergonomic initial sizing consistent with other collectors for the most part, controlling only young gen sizing to rein in pause times. Make CMS young gen sizing default statically cpu-dependant. Remove inconsistencies wrt generation sizing and policy code, allowing for the fixing for 6627787 and 7000125. For 7027529, retire the flag CMSUseOldDefaults which had been introduced as a bridge from JDK 5 to JDK 6 a number of years ago. Reviewed-by: brutisso, poonam
author ysr
date Wed, 16 Mar 2011 10:37:08 -0700
parents c760f78e0a53
children 78bbf4d43a14
line wrap: on
line source

/*
 * Copyright (c) 1999, 2010, 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.
 *
 */

#ifndef SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_INLINE_HPP
#define SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_INLINE_HPP

#include "gc_interface/collectedHeap.hpp"
#include "memory/threadLocalAllocBuffer.hpp"
#include "runtime/atomic.hpp"
#include "runtime/thread.hpp"
#include "utilities/copy.hpp"

inline HeapWord* ThreadLocalAllocBuffer::allocate(size_t size) {
  invariants();
  HeapWord* obj = top();
  if (pointer_delta(end(), obj) >= size) {
    // successful thread-local allocation
#ifdef ASSERT
    // Skip mangling the space corresponding to the object header to
    // ensure that the returned space is not considered parsable by
    // any concurrent GC thread.
    size_t hdr_size = oopDesc::header_size();
    Copy::fill_to_words(obj + hdr_size, size - hdr_size, badHeapWordVal);
#endif // ASSERT
    // This addition is safe because we know that top is
    // at least size below end, so the add can't wrap.
    set_top(obj + size);

    invariants();
    return obj;
  }
  return NULL;
}

inline size_t ThreadLocalAllocBuffer::compute_size(size_t obj_size) {
  const size_t aligned_obj_size = align_object_size(obj_size);

  // Compute the size for the new TLAB.
  // The "last" tlab may be smaller to reduce fragmentation.
  // unsafe_max_tlab_alloc is just a hint.
  const size_t available_size = Universe::heap()->unsafe_max_tlab_alloc(myThread()) /
                                                  HeapWordSize;
  size_t new_tlab_size = MIN2(available_size, desired_size() + aligned_obj_size);

  // Make sure there's enough room for object and filler int[].
  const size_t obj_plus_filler_size = aligned_obj_size + alignment_reserve();
  if (new_tlab_size < obj_plus_filler_size) {
    // If there isn't enough room for the allocation, return failure.
    if (PrintTLAB && Verbose) {
      gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")"
                    " returns failure",
                    obj_size);
    }
    return 0;
  }
  if (PrintTLAB && Verbose) {
    gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")"
                  " returns " SIZE_FORMAT,
                  obj_size, new_tlab_size);
  }
  return new_tlab_size;
}


void ThreadLocalAllocBuffer::record_slow_allocation(size_t obj_size) {
  // Raise size required to bypass TLAB next time. Why? Else there's
  // a risk that a thread that repeatedly allocates objects of one
  // size will get stuck on this slow path.

  set_refill_waste_limit(refill_waste_limit() + refill_waste_limit_increment());

  _slow_allocations++;

  if (PrintTLAB && Verbose) {
    Thread* thrd = myThread();
    gclog_or_tty->print("TLAB: %s thread: "INTPTR_FORMAT" [id: %2d]"
                        " obj: "SIZE_FORMAT
                        " free: "SIZE_FORMAT
                        " waste: "SIZE_FORMAT"\n",
                        "slow", thrd, thrd->osthread()->thread_id(),
                        obj_size, free(), refill_waste_limit());
  }
}

#endif // SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_INLINE_HPP