8227434: G1 predictions may over/underflow with high variance input
Summary: Clamp G1 prediction output to sensible values.
Reviewed-by: lkorinth, sjohanss
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#ifndef SHARE_GC_G1_G1CONCURRENTMARKBITMAP_INLINE_HPP
#define SHARE_GC_G1_G1CONCURRENTMARKBITMAP_INLINE_HPP
#include "gc/g1/g1ConcurrentMarkBitMap.hpp"
#include "gc/shared/markBitMap.inline.hpp"
#include "memory/memRegion.hpp"
#include "utilities/align.hpp"
#include "utilities/bitMap.inline.hpp"
inline bool G1CMBitMap::iterate(G1CMBitMapClosure* cl, MemRegion mr) {
assert(!mr.is_empty(), "Does not support empty memregion to iterate over");
assert(_covered.contains(mr),
"Given MemRegion from " PTR_FORMAT " to " PTR_FORMAT " not contained in heap area",
p2i(mr.start()), p2i(mr.end()));
BitMap::idx_t const end_offset = addr_to_offset(mr.end());
BitMap::idx_t offset = _bm.get_next_one_offset(addr_to_offset(mr.start()), end_offset);
while (offset < end_offset) {
HeapWord* const addr = offset_to_addr(offset);
if (!cl->do_addr(addr)) {
return false;
}
size_t const obj_size = (size_t)((oop)addr)->size();
offset = _bm.get_next_one_offset(offset + (obj_size >> _shifter), end_offset);
}
return true;
}
#endif // SHARE_GC_G1_G1CONCURRENTMARKBITMAP_INLINE_HPP