review for 7029167: add support for conditional card marks

Vladimir Kozlov vladimir.kozlov at
Wed Mar 30 17:24:55 PDT 2011

Looks good then. We may need to switch it ON for Nightly testing.


Tom Rodriguez wrote:
> On Mar 30, 2011, at 5:03 PM, Vladimir Kozlov wrote:
>> Tom,
>> what about arraycopy stubs?
> I don't think they are necessary.  This is really about the performance of concurrent algorithms that are doing a lot of field updates, not eliminating all redundant card marks.
> tom
>> Vladimir
>> Tom Rodriguez wrote:
>>> 7029167: add support for conditional card marks
>>> Reviewed-by:
>>> Repeated updates to the card table can be a source of contention on
>>> multiprocessor machines that can greatly inhibit scalability.  This
>>> adds support in C2 for conditional card marks.  Tested with jbb and
>>> CTW.  At some point this should be turned on automatically when multi
>>> socket machines are detected but that's covered under another bug as
>>> is C1 support.

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