archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-09-20 02:54:35 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

6883834: ParNew: assert(!_g->to()->is_in_reserved(obj),"Scanning field twice?") with LargeObjects tests

Browse source 
Fixed process_chunk_boundaries(), used for parallel card scanning when using ParNew/CMS, so as to prevent double-scanning, or worse, non-scanning of imprecisely marked objects exceeding parallel chunk size. Made some sizing parameters for parallel card scanning diagnostic, disabled ParallelGCRetainPLAB, and elaborated and clarified some comments.

Reviewed-by: stefank, johnc
This commit is contained in:
Y. Srinivas Ramakrishna 2011-05-10 00:33:21 -07:00
parent 90ab9d500c
commit 8e56205189
8 changed files with 297 additions and 140 deletions
Download patch file Download diff file Expand all files Collapse all files

24
hotspot/src/share/vm/memory/cardTableModRefBS.hpp
View file

@ -173,18 +173,17 @@ class CardTableModRefBS: public ModRefBarrierSet {
// A variant of the above that will operate in a parallel mode if
// worker threads are available, and clear the dirty cards as it
// processes them.
// ClearNoncleanCardWrapper cl must wrap the DirtyCardToOopClosure dcto_cl,
// which may itself be modified by the method.
// XXX ??? MemRegionClosure above vs OopsInGenClosure below XXX
// XXX some new_dcto_cl's take OopClosure's, plus as above there are
// some MemRegionClosures. Clean this up everywhere. XXX
void non_clean_card_iterate_possibly_parallel(Space* sp, MemRegion mr,
DirtyCardToOopClosure* dcto_cl,
ClearNoncleanCardWrapper* cl);
OopsInGenClosure* cl, CardTableRS* ct);
private:
// Work method used to implement non_clean_card_iterate_possibly_parallel()
// above in the parallel case.
void non_clean_card_iterate_parallel_work(Space* sp, MemRegion mr,
DirtyCardToOopClosure* dcto_cl,
ClearNoncleanCardWrapper* cl,
OopsInGenClosure* cl, CardTableRS* ct,
int n_threads);
protected:
@ -198,11 +197,6 @@ class CardTableModRefBS: public ModRefBarrierSet {
// *** Support for parallel card scanning.
enum SomeConstantsForParallelism {
StridesPerThread = 2,
CardsPerStrideChunk = 256
};
// This is an array, one element per covered region of the card table.
// Each entry is itself an array, with one element per chunk in the
// covered region. Each entry of these arrays is the lowest non-clean
@ -235,7 +229,7 @@ class CardTableModRefBS: public ModRefBarrierSet {
// covers the given address.
uintptr_t addr_to_chunk_index(const void* addr) {
uintptr_t card = (uintptr_t) byte_for(addr);
return card / CardsPerStrideChunk;
return card / ParGCCardsPerStrideChunk;
}
// Apply cl, which must either itself apply dcto_cl or be dcto_cl,
@ -243,8 +237,8 @@ class CardTableModRefBS: public ModRefBarrierSet {
void process_stride(Space* sp,
MemRegion used,
jint stride, int n_strides,
DirtyCardToOopClosure* dcto_cl,
ClearNoncleanCardWrapper* cl,
OopsInGenClosure* cl,
CardTableRS* ct,
jbyte** lowest_non_clean,
uintptr_t lowest_non_clean_base_chunk_index,
size_t lowest_non_clean_chunk_size);
@ -482,7 +476,7 @@ public:
void verify_dirty_region(MemRegion mr) PRODUCT_RETURN;
static size_t par_chunk_heapword_alignment() {
return CardsPerStrideChunk * card_size_in_words;
return ParGCCardsPerStrideChunk * card_size_in_words;
}
};