RFR(L): 8029075 - String deduplication in G1

[Per Liden]

Hi Thomas,

On 03/05/2014 12:27 PM, Thomas Schatzl wrote:
> Hi again,
>
>    some comment below...
>
> On Wed, 2014-03-05 at 11:56 +0100, Thomas Schatzl wrote:
>> Hi Per,
>>
>> On Mon, 2014-03-03 at 14:33 +0100, Per Liden wrote:
>>> Hi,
>>>
>>> Could I please have this patch reviewed.
>>
>>    this is not a complete review (still working on it), but some comments
>> about measuring the time taken.
>>
>> When printing thread processing times, is it possible to provide
>> per-thread times for the specific parts (queue processing, table
>> processing) and the total?
>>
>> E.g. instead of only the total time for weak root fixup, provide also
>> string table processing time.
>>
>> This would help finding issues with particular phases of the weak root
>> fixup, and in particular string dedup. Per thread times (at maximum
>> logging level) will help finding issues.
>>
>> Potentially this code is trying to distribute little work on hundreds of
>> threads after all and this would help identifying the problem quickly.
>>
>> Something like:
>>
>> [Weak Root Fixup ....]
>>    [String Dedup ...]
>
> Probably it's better that this change only adds the String Dedup entry.

Sure, I can exclude the JNI time for now.

>
>>
>> (Additionally, probably better in a separate CR, add timing for
>> processing the JNI weak root handles).
>
> That separate CR should probably add both "Weak Root Fixup" and "JNI
> Handle Fixup" entries.

Yep, I'll create a separate CR for that.

/Per

>
> Thanks,
>    Thomas
>
>