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

7068625: Testing 8 bytes of card table entries at a time speeds up card-scanning

Browse Source 
Check clean words instead of clean bytes

Reviewed-by: jcoomes, jmasa, jwilhelm, ysr
This commit is contained in:
Alexey Ragozin 2012-03-14 12:49:27 +01:00 committed by Bengt Rutisson
parent 4a2a6ebe99
commit 2c9482428f
3 changed files with 27 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
hotspot/src/share/vm/memory/cardTableModRefBS.hpp
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2012, 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
@ -72,6 +72,9 @@ class CardTableModRefBS: public ModRefBarrierSet {
CT_MR_BS_last_reserved = 16
};
// a word's worth (row) of clean card values
static const intptr_t clean_card_row = (intptr_t)(-1);
// dirty and precleaned are equivalent wrt younger_refs_iter.
static bool card_is_dirty_wrt_gen_iter(jbyte cv) {
return cv == dirty_card || cv == precleaned_card;

17
hotspot/src/share/vm/memory/cardTableRS.cpp
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2001, 2012, 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
@ -173,6 +173,10 @@ ClearNoncleanCardWrapper::ClearNoncleanCardWrapper(
SharedHeap::heap()->workers()->active_workers()), "Mismatch");
}
bool ClearNoncleanCardWrapper::is_word_aligned(jbyte* entry) {
return (((intptr_t)entry) & (BytesPerWord-1)) == 0;
}
void ClearNoncleanCardWrapper::do_MemRegion(MemRegion mr) {
assert(mr.word_size() > 0, "Error");
assert(_ct->is_aligned(mr.start()), "mr.start() should be card aligned");
@ -194,6 +198,17 @@ void ClearNoncleanCardWrapper::do_MemRegion(MemRegion mr) {
const MemRegion mrd(start_of_non_clean, end_of_non_clean);
_dirty_card_closure->do_MemRegion(mrd);
}
// fast forward through potential continuous whole-word range of clean cards beginning at a word-boundary
if (is_word_aligned(cur_entry)) {
jbyte* cur_row = cur_entry - BytesPerWord;
while (cur_row >= limit && *((intptr_t*)cur_row) == CardTableRS::clean_card_row()) {
cur_row -= BytesPerWord;
}
cur_entry = cur_row + BytesPerWord;
cur_hw = _ct->addr_for(cur_entry);
}
// Reset the dirty window, while continuing to look
// for the next dirty card that will start a
// new dirty window.

8
hotspot/src/share/vm/memory/cardTableRS.hpp
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2001, 2012, 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
@ -45,6 +45,10 @@ class CardTableRS: public GenRemSet {
return CardTableModRefBS::clean_card;
}
static intptr_t clean_card_row() {
return CardTableModRefBS::clean_card_row;
}
static bool
card_is_dirty_wrt_gen_iter(jbyte cv) {
return CardTableModRefBS::card_is_dirty_wrt_gen_iter(cv);
@ -176,6 +180,8 @@ private:
// Work methods called by the clear_card()
inline bool clear_card_serial(jbyte* entry);
inline bool clear_card_parallel(jbyte* entry);
// check alignment of pointer
bool is_word_aligned(jbyte* entry);
public:
ClearNoncleanCardWrapper(DirtyCardToOopClosure* dirty_card_closure, CardTableRS* ct);