diff -r 7fcd5f39bd7a -r be3f9c242c9d src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp --- a/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp Sat Aug 14 00:47:52 2010 -0700 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp Mon Aug 16 15:58:42 2010 -0700 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2009, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 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 @@ -402,6 +402,29 @@ return res; } +void LinearAllocBlock::print_on(outputStream* st) const { + st->print_cr(" LinearAllocBlock: ptr = " PTR_FORMAT ", word_size = " SIZE_FORMAT + ", refillsize = " SIZE_FORMAT ", allocation_size_limit = " SIZE_FORMAT, + _ptr, _word_size, _refillSize, _allocation_size_limit); +} + +void CompactibleFreeListSpace::print_on(outputStream* st) const { + st->print_cr("COMPACTIBLE FREELIST SPACE"); + st->print_cr(" Space:"); + Space::print_on(st); + + st->print_cr("promoInfo:"); + _promoInfo.print_on(st); + + st->print_cr("_smallLinearAllocBlock"); + _smallLinearAllocBlock.print_on(st); + + // dump_memory_block(_smallLinearAllocBlock->_ptr, 128); + + st->print_cr(" _fitStrategy = %s, _adaptive_freelists = %s", + _fitStrategy?"true":"false", _adaptive_freelists?"true":"false"); +} + void CompactibleFreeListSpace::print_indexed_free_lists(outputStream* st) const { reportIndexedFreeListStatistics(); @@ -557,13 +580,15 @@ void CompactibleFreeListSpace::set_end(HeapWord* value) { HeapWord* prevEnd = end(); assert(prevEnd != value, "unnecessary set_end call"); - assert(prevEnd == NULL || value >= unallocated_block(), "New end is below unallocated block"); + assert(prevEnd == NULL || !BlockOffsetArrayUseUnallocatedBlock || value >= unallocated_block(), + "New end is below unallocated block"); _end = value; if (prevEnd != NULL) { // Resize the underlying block offset table. _bt.resize(pointer_delta(value, bottom())); if (value <= prevEnd) { - assert(value >= unallocated_block(), "New end is below unallocated block"); + assert(!BlockOffsetArrayUseUnallocatedBlock || value >= unallocated_block(), + "New end is below unallocated block"); } else { // Now, take this new chunk and add it to the free blocks. // Note that the BOT has not yet been updated for this block. @@ -938,7 +963,6 @@ size_t CompactibleFreeListSpace::block_size(const HeapWord* p) const { NOT_PRODUCT(verify_objects_initialized()); - assert(MemRegion(bottom(), end()).contains(p), "p not in space"); // This must be volatile, or else there is a danger that the compiler // will compile the code below into a sometimes-infinite loop, by keeping // the value read the first time in a register. @@ -957,7 +981,7 @@ // must read from what 'p' points to in each loop. klassOop k = ((volatile oopDesc*)p)->klass_or_null(); if (k != NULL) { - assert(k->is_oop(true /* ignore mark word */), "Should really be klass oop."); + assert(k->is_oop(true /* ignore mark word */), "Should be klass oop"); oop o = (oop)p; assert(o->is_parsable(), "Should be parsable"); assert(o->is_oop(true /* ignore mark word */), "Should be an oop."); @@ -1231,7 +1255,6 @@ // satisfy the request. This is different that // evm. // Don't record chunk off a LinAB? smallSplitBirth(size); - } else { // Raid the exact free lists larger than size, even if they are not // overpopulated. @@ -1449,6 +1472,7 @@ // Update BOT last so that other (parallel) GC threads see a consistent // view of the BOT and free blocks. // Above must occur before BOT is updated below. + OrderAccess::storestore(); _bt.split_block(res, blk_size, size); // adjust block offset table } return res; @@ -1477,6 +1501,7 @@ // Update BOT last so that other (parallel) GC threads see a consistent // view of the BOT and free blocks. // Above must occur before BOT is updated below. + OrderAccess::storestore(); _bt.split_block(res, blk_size, size); // adjust block offset table _bt.allocated(res, size); } @@ -1856,6 +1881,8 @@ ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. // Above must occur before BOT is updated below. // adjust block offset table + OrderAccess::storestore(); + assert(chunk->isFree() && ffc->isFree(), "Error"); _bt.split_block((HeapWord*)chunk, chunk->size(), new_size); if (rem_size < SmallForDictionary) { bool is_par = (SharedHeap::heap()->n_par_threads() > 0); @@ -1911,8 +1938,7 @@ // mark the "end" of the used space at the time of this call; // note, however, that promoted objects from this point // on are tracked in the _promoInfo below. - set_saved_mark_word(BlockOffsetArrayUseUnallocatedBlock ? - unallocated_block() : end()); + set_saved_mark_word(unallocated_block()); // inform allocator that promotions should be tracked. assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); _promoInfo.startTrackingPromotions(); @@ -2238,8 +2264,7 @@ } void CompactibleFreeListSpace::print() const { - tty->print(" CompactibleFreeListSpace"); - Space::print(); + Space::print_on(tty); } void CompactibleFreeListSpace::prepare_for_verify() { @@ -2253,18 +2278,28 @@ private: const CompactibleFreeListSpace* _sp; const MemRegion _span; + HeapWord* _last_addr; + size_t _last_size; + bool _last_was_obj; + bool _last_was_live; public: VerifyAllBlksClosure(const CompactibleFreeListSpace* sp, - MemRegion span) : _sp(sp), _span(span) { } + MemRegion span) : _sp(sp), _span(span), + _last_addr(NULL), _last_size(0), + _last_was_obj(false), _last_was_live(false) { } virtual size_t do_blk(HeapWord* addr) { size_t res; + bool was_obj = false; + bool was_live = false; if (_sp->block_is_obj(addr)) { + was_obj = true; oop p = oop(addr); guarantee(p->is_oop(), "Should be an oop"); res = _sp->adjustObjectSize(p->size()); if (_sp->obj_is_alive(addr)) { + was_live = true; p->verify(); } } else { @@ -2275,7 +2310,20 @@ "Chunk should be on a free list"); } } - guarantee(res != 0, "Livelock: no rank reduction!"); + if (res == 0) { + gclog_or_tty->print_cr("Livelock: no rank reduction!"); + gclog_or_tty->print_cr( + " Current: addr = " PTR_FORMAT ", size = " SIZE_FORMAT ", obj = %s, live = %s \n" + " Previous: addr = " PTR_FORMAT ", size = " SIZE_FORMAT ", obj = %s, live = %s \n", + addr, res, was_obj ?"true":"false", was_live ?"true":"false", + _last_addr, _last_size, _last_was_obj?"true":"false", _last_was_live?"true":"false"); + _sp->print_on(gclog_or_tty); + guarantee(false, "Seppuku!"); + } + _last_addr = addr; + _last_size = res; + _last_was_obj = was_obj; + _last_was_live = was_live; return res; } }; @@ -2521,7 +2569,7 @@ HeapWord* CFLS_LAB::alloc(size_t word_sz) { FreeChunk* res; - word_sz = _cfls->adjustObjectSize(word_sz); + guarantee(word_sz == _cfls->adjustObjectSize(word_sz), "Error"); if (word_sz >= CompactibleFreeListSpace::IndexSetSize) { // This locking manages sync with other large object allocations. MutexLockerEx x(_cfls->parDictionaryAllocLock(), @@ -2667,12 +2715,12 @@ (cur_sz < CompactibleFreeListSpace::IndexSetSize) && (CMSSplitIndexedFreeListBlocks || k <= 1); k++, cur_sz = k * word_sz) { - FreeList* gfl = &_indexedFreeList[cur_sz]; FreeList fl_for_cur_sz; // Empty. fl_for_cur_sz.set_size(cur_sz); { MutexLockerEx x(_indexedFreeListParLocks[cur_sz], Mutex::_no_safepoint_check_flag); + FreeList* gfl = &_indexedFreeList[cur_sz]; if (gfl->count() != 0) { // nn is the number of chunks of size cur_sz that // we'd need to split k-ways each, in order to create @@ -2685,9 +2733,9 @@ // we increment the split death count by the number of blocks // we just took from the cur_sz-size blocks list and which // we will be splitting below. - ssize_t deaths = _indexedFreeList[cur_sz].splitDeaths() + + ssize_t deaths = gfl->splitDeaths() + fl_for_cur_sz.count(); - _indexedFreeList[cur_sz].set_splitDeaths(deaths); + gfl->set_splitDeaths(deaths); } } } @@ -2703,18 +2751,25 @@ // access the main chunk sees it as a single free block until we // change it. size_t fc_size = fc->size(); + assert(fc->isFree(), "Error"); for (int i = k-1; i >= 0; i--) { FreeChunk* ffc = (FreeChunk*)((HeapWord*)fc + i * word_sz); + assert((i != 0) || + ((fc == ffc) && ffc->isFree() && + (ffc->size() == k*word_sz) && (fc_size == word_sz)), + "Counting error"); ffc->setSize(word_sz); + ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. ffc->linkNext(NULL); - ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. // Above must occur before BOT is updated below. - // splitting from the right, fc_size == (k - i + 1) * wordsize - _bt.mark_block((HeapWord*)ffc, word_sz); + OrderAccess::storestore(); + // splitting from the right, fc_size == i * word_sz + _bt.mark_block((HeapWord*)ffc, word_sz, true /* reducing */); fc_size -= word_sz; - _bt.verify_not_unallocated((HeapWord*)ffc, ffc->size()); + assert(fc_size == i*word_sz, "Error"); + _bt.verify_not_unallocated((HeapWord*)ffc, word_sz); _bt.verify_single_block((HeapWord*)fc, fc_size); - _bt.verify_single_block((HeapWord*)ffc, ffc->size()); + _bt.verify_single_block((HeapWord*)ffc, word_sz); // Push this on "fl". fl->returnChunkAtHead(ffc); } @@ -2744,7 +2799,7 @@ _dictionary->minSize()), FreeBlockDictionary::atLeast); if (fc != NULL) { - _bt.allocated((HeapWord*)fc, fc->size()); // update _unallocated_blk + _bt.allocated((HeapWord*)fc, fc->size(), true /* reducing */); // update _unallocated_blk dictionary()->dictCensusUpdate(fc->size(), true /*split*/, false /*birth*/); @@ -2754,8 +2809,10 @@ } } if (fc == NULL) return; + // Otherwise, split up that block. assert((ssize_t)n >= 1, "Control point invariant"); - // Otherwise, split up that block. + assert(fc->isFree(), "Error: should be a free block"); + _bt.verify_single_block((HeapWord*)fc, fc->size()); const size_t nn = fc->size() / word_sz; n = MIN2(nn, n); assert((ssize_t)n >= 1, "Control point invariant"); @@ -2773,6 +2830,7 @@ // dictionary and return, leaving "fl" empty. if (n == 0) { returnChunkToDictionary(fc); + assert(fl->count() == 0, "We never allocated any blocks"); return; } @@ -2785,11 +2843,14 @@ size_t prefix_size = n * word_sz; rem_fc = (FreeChunk*)((HeapWord*)fc + prefix_size); rem_fc->setSize(rem); + rem_fc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. rem_fc->linkNext(NULL); - rem_fc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. // Above must occur before BOT is updated below. assert((ssize_t)n > 0 && prefix_size > 0 && rem_fc > fc, "Error"); + OrderAccess::storestore(); _bt.split_block((HeapWord*)fc, fc->size(), prefix_size); + assert(fc->isFree(), "Error"); + fc->setSize(prefix_size); if (rem >= IndexSetSize) { returnChunkToDictionary(rem_fc); dictionary()->dictCensusUpdate(rem, true /*split*/, true /*birth*/); @@ -2815,11 +2876,12 @@ for (ssize_t i = n-1; i > 0; i--) { FreeChunk* ffc = (FreeChunk*)((HeapWord*)fc + i * word_sz); ffc->setSize(word_sz); + ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. ffc->linkNext(NULL); - ffc->linkPrev(NULL); // Mark as a free block for other (parallel) GC threads. // Above must occur before BOT is updated below. + OrderAccess::storestore(); // splitting from the right, fc_size == (n - i + 1) * wordsize - _bt.mark_block((HeapWord*)ffc, word_sz); + _bt.mark_block((HeapWord*)ffc, word_sz, true /* reducing */); fc_size -= word_sz; _bt.verify_not_unallocated((HeapWord*)ffc, ffc->size()); _bt.verify_single_block((HeapWord*)ffc, ffc->size()); @@ -2828,9 +2890,11 @@ fl->returnChunkAtHead(ffc); } // First chunk + assert(fc->isFree() && fc->size() == n*word_sz, "Error: should still be a free block"); + // The blocks above should show their new sizes before the first block below fc->setSize(word_sz); + fc->linkPrev(NULL); // idempotent wrt free-ness, see assert above fc->linkNext(NULL); - fc->linkPrev(NULL); _bt.verify_not_unallocated((HeapWord*)fc, fc->size()); _bt.verify_single_block((HeapWord*)fc, fc->size()); fl->returnChunkAtHead(fc);