RFR(S): 8008301: G1: guarantee(satb_mq_set.completed_buffers_num() == 0) failure
john.cuthbertson at oracle.com
Fri Mar 15 11:54:38 PDT 2013
Thanks for the review.
On 3/15/2013 9:32 AM, Jon Masamitsu wrote:
> Looks good.
> On 3/14/2013 5:31 PM, John Cuthbertson wrote:
>> Hi Everyone,
>> Here's another one associated with overflowing the marking stack. The
>> webrev can be found at:
>> In this case the marking stack overflows during the actual remark
>> task - when the individual marking tasks are draining the completed
>> SATB buffers. As a result we exit the remark task (because of the
>> overflow) with some legitimately unprocessed completed SATB buffers
>> and trip the guarantee.
>> The main part of the fix is between line 2575 and 2579 where I relax
>> the guarantee to allow for the overflow. Additionally I've also added
>> a heap verification for when we restart marking due to overflow. I
>> added it as part of the debugging and I think it makes sense to leave
>> it in.
>> The change between lines 2408 and 2416 is to just skip reference
>> processing. While testing I was running into the hang reported in
>> 8009536 and added this to work around it. An equivalent change will
>> be pushed as part of the changes for 8009940.
>> The failing test case in a loop (with and without instrumentation and
>> The GC test suite with a small mark stack size (2K, 4K)
>> The Lucene tests for 8009536 to specifically test the verification
>> after overflow.
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