Mercurial > hg > truffle
diff src/share/vm/gc_implementation/g1/g1MMUTracker.cpp @ 1088:3fc996d4edd2
6902303: G1: ScavengeALot should cause an incremental, rather than a full, collection
Summary: ScavengeALot now causes an incremental (but possibly partially young, in the G1 sense) collection. Some such collections may be abandoned on account of MMU specs. Band-aided a native leak associated with abandoned pauses, as well as an MMU tracker overflow related to frequent scavenge events in the face of a large MMU denominator interval; the latter is protected by a product flag that defaults to false.
Reviewed-by: tonyp
| author | ysr |
|---|---|
| date | Thu, 19 Nov 2009 13:43:25 -0800 |
| parents | 89e0543e1737 |
| children | b81f3572f355 |
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--- a/src/share/vm/gc_implementation/g1/g1MMUTracker.cpp Thu Nov 19 10:19:19 2009 -0800 +++ b/src/share/vm/gc_implementation/g1/g1MMUTracker.cpp Thu Nov 19 13:43:25 2009 -0800 @@ -86,12 +86,22 @@ // increase the array size (:-) // remove the oldest entry (this might allow more GC time for // the time slice than what's allowed) - // concolidate the two entries with the minimum gap between them - // (this mighte allow less GC time than what's allowed) - guarantee(0, "array full, currently we can't recover"); + // consolidate the two entries with the minimum gap between them + // (this might allow less GC time than what's allowed) + guarantee(NOT_PRODUCT(ScavengeALot ||) G1ForgetfulMMUTracker, + "array full, currently we can't recover unless +G1ForgetfulMMUTracker"); + // In the case where ScavengeALot is true, such overflow is not + // uncommon; in such cases, we can, without much loss of precision + // or performance (we are GC'ing most of the time anyway!), + // simply overwrite the oldest entry in the tracker: this + // is also the behaviour when G1ForgetfulMMUTracker is enabled. + _head_index = trim_index(_head_index + 1); + assert(_head_index == _tail_index, "Because we have a full circular buffer"); + _tail_index = trim_index(_tail_index + 1); + } else { + _head_index = trim_index(_head_index + 1); + ++_no_entries; } - _head_index = trim_index(_head_index + 1); - ++_no_entries; _array[_head_index] = G1MMUTrackerQueueElem(start, end); }