[8u] RFR 8158871: Long response times with G1 and StringDeduplication

[Per Liden]

On 2016-06-30 13:57, Vladimir Kempik wrote:
> Hello
>
> Thanks for the comment Per.
>
> Here is updated webrev -
> http://cr.openjdk.java.net/~vkempik/8158871/webrev.01/

Looks good.

/Per

>
> Can I have some jdk8 reviewer to take quick look at this as well?
>
> Thanks.
>
> On 30.06.2016 10:14, Per Liden wrote:
>> Hi,
>>
>> On 2016-06-29 17:39, Vladimir Kempik wrote:
>>> Hello
>>>
>>> Please review this backport of 8158871 to jdk8u.
>>>
>>> Few changes for jdk8 were applied:
>>>
>>> 1) universall logging call changed to gclog_or_tty->print_cr
>>>
>>> 2) added casting of multiplication result (size_t * double) to size_t
>>> because on macosx platform the result was casted to double:
>>>
>>>   _entry_cache = new G1StringDedupEntryCache((size_t)(_min_size *
>>> _max_cache_factor));
>>> ...
>>>   _entry_cache->set_max_size((size_t)(size * _max_cache_factor));
>>>
>>>
>>>
>>>
>>> Testing: jprt
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8158871
>>> Webrev: http://cr.openjdk.java.net/~vkempik/8158871/webrev.00/
>>
>>
>> src/share/vm/gc_implementation/g1/g1StringDedupTable.cpp
>> --------------------------------------------------------
>> Since we don't have unified logging in 8 you need to check the
>> PrintStringDeduplicationStatistics flags before printing "Deleted...".
>> Also, since we don't have decorating tags we need more context in the
>> printout. I suggest "[GC concurrent-string-deduplication, deleted X
>> entries, X.XXX secs]".
>>
>> So, the incremental change would be:
>>
>> -  gclog_or_tty->print_cr("Deleted " UINTX_FORMAT " entries, "
>> G1_STRDEDUP_TIME_FORMAT, count, end - start);
>> +  if (PrintStringDeduplicationStatistics) {
>> +    gclog_or_tty->print_cr("[GC concurrent-string-deduplication,
>> deleted " UINTX_FORMAT " entries, " G1_STRDEDUP_TIME_FORMAT "]",
>> count, end - start);
>> +  }
>>
>>
>> Other than that, the patch looks good.
>>
>> cheers,
>> /Per
>>
>>>
>>> Thanks
>>> -Vladimir
>>>
>