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6420645: Create a vm that uses compressed oops for up to 32gb heapsizes

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Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv

Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold
This commit is contained in:
Coleen Phillimore 2008-04-13 17:43:42 -04:00
parent 680ecf1611
commit 4a831d45f0
273 changed files with 6585 additions and 2993 deletions
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25
hotspot/src/share/vm/runtime/arguments.cpp
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@ -1163,6 +1163,31 @@ void Arguments::set_ergonomics_flags() {
no_shared_spaces();
}
}
#ifdef _LP64
// Compressed Headers do not work with CMS, which uses a bit in the klass
// field offset to determine free list chunk markers.
// Check that UseCompressedOops can be set with the max heap size allocated
// by ergonomics.
if (!UseConcMarkSweepGC && MaxHeapSize <= (32*G - os::vm_page_size())) {
if (FLAG_IS_DEFAULT(UseCompressedOops)) {
FLAG_SET_ERGO(bool, UseCompressedOops, true);
}
} else {
if (UseCompressedOops && !FLAG_IS_DEFAULT(UseCompressedOops)) {
// If specified, give a warning
if (UseConcMarkSweepGC){
warning("Compressed Oops does not work with CMS");
} else {
warning(
"Max heap size too large for Compressed Oops");
}
FLAG_SET_DEFAULT(UseCompressedOops, false);
}
}
// Also checks that certain machines are slower with compressed oops
// in vm_version initialization code.
#endif // _LP64
}
void Arguments::set_parallel_gc_flags() {