stan/jdk-24
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

6483129: par compact assertion failure (new_top > bottom)

Browse Source 
Avoid computing the dense prefix if a space is empty

Reviewed-by: pbk, tonyp
This commit is contained in:
John Coomes 2008-07-11 16:11:43 -07:00
parent 398aa66a77
commit 038a30dde3
1 changed files with 29 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
View File

@ -1524,48 +1524,53 @@ void
PSParallelCompact::summarize_space(SpaceId id, bool maximum_compaction)
{
assert(id < last_space_id, "id out of range");
assert(_space_info[id].dense_prefix() == _space_info[id].space()->bottom(),
"should have been set in summarize_spaces_quick()");
const MutableSpace* space = _space_info[id].space();
HeapWord** new_top_addr = _space_info[id].new_top_addr();
HeapWord* dense_prefix_end = compute_dense_prefix(id, maximum_compaction);
_space_info[id].set_dense_prefix(dense_prefix_end);
if (_space_info[id].new_top() != space->bottom()) {
HeapWord* dense_prefix_end = compute_dense_prefix(id, maximum_compaction);
_space_info[id].set_dense_prefix(dense_prefix_end);
#ifndef PRODUCT
if (TraceParallelOldGCDensePrefix) {
print_dense_prefix_stats("ratio", id, maximum_compaction, dense_prefix_end);
HeapWord* addr = compute_dense_prefix_via_density(id, maximum_compaction);
print_dense_prefix_stats("density", id, maximum_compaction, addr);
}
if (TraceParallelOldGCDensePrefix) {
print_dense_prefix_stats("ratio", id, maximum_compaction,
dense_prefix_end);
HeapWord* addr = compute_dense_prefix_via_density(id, maximum_compaction);
print_dense_prefix_stats("density", id, maximum_compaction, addr);
}
#endif // #ifndef PRODUCT
// If dead space crosses the dense prefix boundary, it is (at least partially)
// filled with a dummy object, marked live and added to the summary data.
// This simplifies the copy/update phase and must be done before the final
// locations of objects are determined, to prevent leaving a fragment of dead
// space that is too small to fill with an object.
if (!maximum_compaction && dense_prefix_end != space->bottom()) {
fill_dense_prefix_end(id);
}
// If dead space crosses the dense prefix boundary, it is (at least
// partially) filled with a dummy object, marked live and added to the
// summary data. This simplifies the copy/update phase and must be done
// before the final locations of objects are determined, to prevent leaving
// a fragment of dead space that is too small to fill with an object.
if (!maximum_compaction && dense_prefix_end != space->bottom()) {
fill_dense_prefix_end(id);
}
// Compute the destination of each Chunk, and thus each object.
_summary_data.summarize_dense_prefix(space->bottom(), dense_prefix_end);
_summary_data.summarize(dense_prefix_end, space->end(),
dense_prefix_end, space->top(),
new_top_addr);
// Compute the destination of each Chunk, and thus each object.
_summary_data.summarize_dense_prefix(space->bottom(), dense_prefix_end);
_summary_data.summarize(dense_prefix_end, space->end(),
dense_prefix_end, space->top(),
_space_info[id].new_top_addr());
}
if (TraceParallelOldGCSummaryPhase) {
const size_t chunk_size = ParallelCompactData::ChunkSize;
HeapWord* const dense_prefix_end = _space_info[id].dense_prefix();
const size_t dp_chunk = _summary_data.addr_to_chunk_idx(dense_prefix_end);
const size_t dp_words = pointer_delta(dense_prefix_end, space->bottom());
const HeapWord* nt_aligned_up = _summary_data.chunk_align_up(*new_top_addr);
HeapWord* const new_top = _space_info[id].new_top();
const HeapWord* nt_aligned_up = _summary_data.chunk_align_up(new_top);
const size_t cr_words = pointer_delta(nt_aligned_up, dense_prefix_end);
tty->print_cr("id=%d cap=" SIZE_FORMAT " dp=" PTR_FORMAT " "
"dp_chunk=" SIZE_FORMAT " " "dp_count=" SIZE_FORMAT " "
"cr_count=" SIZE_FORMAT " " "nt=" PTR_FORMAT,
id, space->capacity_in_words(), dense_prefix_end,
dp_chunk, dp_words / chunk_size,
cr_words / chunk_size, *new_top_addr);
cr_words / chunk_size, new_top);
}
}