Mercurial > hg > release > icedtea7-forest-2.6 > hotspot
changeset 3744:c7a555a9449a
7068625: Testing 8 bytes of card table entries at a time speeds up card-scanning
Summary: Check clean words instead of clean bytes
Reviewed-by: jcoomes, jmasa, jwilhelm, ysr
Contributed-by: alexey.ragozin@gmail.com
| author | brutisso |
|---|---|
| date | Wed, 14 Mar 2012 12:49:27 +0100 |
| parents | 2c0751569716 |
| children | f96bddf3d3f3 |
| files | src/share/vm/memory/cardTableModRefBS.hpp src/share/vm/memory/cardTableRS.cpp src/share/vm/memory/cardTableRS.hpp |
| diffstat | 3 files changed, 27 insertions(+), 3 deletions(-) [+] |
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--- a/src/share/vm/memory/cardTableModRefBS.hpp Tue Mar 13 21:12:53 2012 +0100 +++ b/src/share/vm/memory/cardTableModRefBS.hpp Wed Mar 14 12:49:27 2012 +0100 @@ -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 @@ 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;
--- a/src/share/vm/memory/cardTableRS.cpp Tue Mar 13 21:12:53 2012 +0100 +++ b/src/share/vm/memory/cardTableRS.cpp Wed Mar 14 12:49:27 2012 +0100 @@ -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 @@ 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 @@ 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.
--- a/src/share/vm/memory/cardTableRS.hpp Tue Mar 13 21:12:53 2012 +0100 +++ b/src/share/vm/memory/cardTableRS.hpp Wed Mar 14 12:49:27 2012 +0100 @@ -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 @@ 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 @@ // 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);