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8152176: Big ParGCCardsPerStrideChunk values can cause overflow for CMS GC

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Limit the max value of ParGCCardsPerStrideChunk based on card table size and other stride flags

Reviewed-by: jmasa, tbenson
This commit is contained in:
Sangheon Kim 2016-04-01 09:43:13 -07:00
parent c3469071aa
commit a868617af7
4 changed files with 44 additions and 9 deletions
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18
hotspot/src/share/vm/gc/shared/cardTableModRefBS.hpp
View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2016, 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
@ -89,14 +89,6 @@ class CardTableModRefBS: public ModRefBarrierSet {
MemRegion _guard_region;
protected:
// Initialization utilities; covered_words is the size of the covered region
// in, um, words.
inline size_t cards_required(size_t covered_words) {
// Add one for a guard card, used to detect errors.
const size_t words = align_size_up(covered_words, card_size_in_words);
return words / card_size_in_words + 1;
}
inline size_t compute_byte_map_size();
// Finds and return the index of the region, if any, to which the given
@ -172,6 +164,14 @@ public:
bool has_write_ref_pre_barrier() { return false; }
// Initialization utilities; covered_words is the size of the covered region
// in, um, words.
inline size_t cards_required(size_t covered_words) {
// Add one for a guard card, used to detect errors.
const size_t words = align_size_up(covered_words, card_size_in_words);
return words / card_size_in_words + 1;
}
protected:
CardTableModRefBS(MemRegion whole_heap, const BarrierSet::FakeRtti& fake_rtti);

33
hotspot/src/share/vm/runtime/commandLineFlagConstraintsGC.cpp
View file

@ -382,6 +382,39 @@ Flag::Error ParGCStridesPerThreadConstraintFunc(uintx value, bool verbose) {
return Flag::SUCCESS;
}
Flag::Error ParGCCardsPerStrideChunkConstraintFunc(intx value, bool verbose) {
#if INCLUDE_ALL_GCS
if (UseConcMarkSweepGC) {
// ParGCCardsPerStrideChunk should be compared with card table size.
size_t heap_size = Universe::heap()->reserved_region().word_size();
CardTableModRefBS* bs = (CardTableModRefBS*)GenCollectedHeap::heap()->rem_set()->bs();
size_t card_table_size = bs->cards_required(heap_size) - 1; // Valid card table size
if ((size_t)value > card_table_size) {
CommandLineError::print(verbose,
"ParGCCardsPerStrideChunk (" INTX_FORMAT ") is too large for the heap size and "
"must be less than or equal to card table size (" SIZE_FORMAT ")\n",
value, card_table_size);
return Flag::VIOLATES_CONSTRAINT;
}
// ParGCCardsPerStrideChunk is used with n_strides(ParallelGCThreads*ParGCStridesPerThread)
// from CardTableModRefBSForCTRS::process_stride(). Note that ParGCStridesPerThread is already checked
// not to make an overflow with ParallelGCThreads from its constraint function.
uintx n_strides = ParallelGCThreads * ParGCStridesPerThread;
uintx ergo_max = max_uintx / n_strides;
if ((uintx)value > ergo_max) {
CommandLineError::print(verbose,
"ParGCCardsPerStrideChunk (" INTX_FORMAT ") must be "
"less than or equal to ergonomic maximum (" UINTX_FORMAT ")\n",
value, ergo_max);
return Flag::VIOLATES_CONSTRAINT;
}
}
#endif
return Flag::SUCCESS;
}
Flag::Error CMSOldPLABMinConstraintFunc(size_t value, bool verbose) {
Flag::Error status = Flag::SUCCESS;

1
hotspot/src/share/vm/runtime/commandLineFlagConstraintsGC.hpp
View file

@ -56,6 +56,7 @@ Flag::Error G1MaxNewSizePercentConstraintFunc(uintx value, bool verbose);
#endif // INCLUDE_ALL_GCS
Flag::Error ParGCStridesPerThreadConstraintFunc(uintx value, bool verbose);
Flag::Error ParGCCardsPerStrideChunkConstraintFunc(intx value, bool verbose);
Flag::Error CMSOldPLABMinConstraintFunc(size_t value, bool verbose);
Flag::Error CMSOldPLABMaxConstraintFunc(size_t value, bool verbose);
Flag::Error MarkStackSizeConstraintFunc(size_t value, bool verbose);

1
hotspot/src/share/vm/runtime/globals.hpp
View file

@ -1629,6 +1629,7 @@ public:
"The number of cards in each chunk of the parallel chunks used " \
"during card table scanning") \
range(1, max_intx) \
constraint(ParGCCardsPerStrideChunkConstraintFunc,AfterMemoryInit)\
\
product(uintx, OldPLABWeight, 50, \
"Percentage (0-100) used to weight the current sample when " \