Mercurial > hg > truffle
diff src/share/vm/memory/cardTableRS.cpp @ 3293:1f4413413144
7039089: G1: changeset for 7037276 broke heap verification, and related cleanups
Summary: In G1 heap verification, we no longer scan perm to G1-collected heap refs as part of process_strong_roots() but rather in a separate explicit oop iteration over the perm gen. This preserves the original perm card-marks. Added a new assertion in younger_refs_iterate() to catch a simple subcase where the user may have forgotten a prior save_marks() call, as happened in the case of G1's attempt to iterate perm to G1 refs when verifying the heap before exit. The assert was deliberately weakened for ParNew+CMS and will be fixed for that combination in a future CR. Also made some (non-G1) cleanups related to code and comments obsoleted by the migration of Symbols to the native heap.
Reviewed-by: iveresov, jmasa, tonyp
author | ysr |
---|---|
date | Tue, 26 Apr 2011 21:17:24 -0700 |
parents | c48ad6ab8bdf |
children | fc2b798ab316 |
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--- a/src/share/vm/memory/cardTableRS.cpp Tue Apr 26 11:46:34 2011 -0700 +++ b/src/share/vm/memory/cardTableRS.cpp Tue Apr 26 21:17:24 2011 -0700 @@ -250,7 +250,34 @@ cl->gen_boundary()); ClearNoncleanCardWrapper clear_cl(dcto_cl, this); - _ct_bs->non_clean_card_iterate_possibly_parallel(sp, sp->used_region_at_save_marks(), + const MemRegion urasm = sp->used_region_at_save_marks(); +#ifdef ASSERT + // Convert the assertion check to a warning if we are running + // CMS+ParNew until related bug is fixed. + MemRegion ur = sp->used_region(); + assert(ur.contains(urasm) || (UseConcMarkSweepGC && UseParNewGC), + err_msg("Did you forget to call save_marks()? " + "[" PTR_FORMAT ", " PTR_FORMAT ") is not contained in " + "[" PTR_FORMAT ", " PTR_FORMAT ")", + urasm.start(), urasm.end(), ur.start(), ur.end())); + // In the case of CMS+ParNew, issue a warning + if (!ur.contains(urasm)) { + assert(UseConcMarkSweepGC && UseParNewGC, "Tautology: see assert above"); + warning("CMS+ParNew: Did you forget to call save_marks()? " + "[" PTR_FORMAT ", " PTR_FORMAT ") is not contained in " + "[" PTR_FORMAT ", " PTR_FORMAT ")", + urasm.start(), urasm.end(), ur.start(), ur.end()); + MemRegion ur2 = sp->used_region(); + MemRegion urasm2 = sp->used_region_at_save_marks(); + if (!ur.equals(ur2)) { + warning("CMS+ParNew: Flickering used_region()!!"); + } + if (!urasm.equals(urasm2)) { + warning("CMS+ParNew: Flickering used_region_at_save_marks()!!"); + } + } +#endif + _ct_bs->non_clean_card_iterate_possibly_parallel(sp, urasm, dcto_cl, &clear_cl); }