RFR (L) 8151711: Move G1 number sequences out of the G1 collector policy

[Tom Benson]

Hi,
It looks like the name change makes the indentation wrong at lines 244, 871, and 876 in g1CollectorPolicy.cpp,
and at 320 in g1Analytics.cpp.  Aside from that, looks good!
Tom

On 3/16/2016 10:36 AM, Erik Helin wrote:
> On 2016-03-16, Mikael Gerdin wrote:
>> Hi Tom,
>>
>> Thanks for the review!
>>
>> On 2016-03-15 20:37, Tom Benson wrote:
>>> Hi Mikael,
>>> This looks OK to me, with one trivial comment.  Since you're making a
>>> new module out of it, perhaps you can make the indentation at lines
>>> 105-112 in g1Measurements.cpp more consistent.
>> Fixed.
>>
>>> If feels like maybe the existing G1Predictions.cpp/.hpp should be folded
>>> into this new module, now that the measurement stuff is separate from
>>> Policy.  It's very small - most of the code is a test.  But I suppose
>>> that could be the subject of another change.
>> My thought with not moving G1Predictions into the new module was to allow
>> the tunables of the predictor to be set elsewhere.
>>
>>> As for names, G1Analytics came to mind to imply data gathering and
>>> prediction.
>> I like that name!
>>
>> I also got some offline feedback from Erik indicating that
>> update_recent_gc_times was actually called from full gcs as well and in that
>> case didn't do the ratio calculations so I rewrote the code to
>>
>>      double interval_ms =
>>        (end_time_sec - _analytics->last_known_gc_end_time_sec()) * 1000.0;
>>      _analytics->update_recent_gc_times(end_time_sec, pause_time_ms);
>>      _analytics->compute_pause_time_ratio(interval_ms, pause_time_ms);
>>    }
> Looks good besides a space on the wrong side of the comma:
> +    _analytics->predict_object_copy_time_ms(bytes_to_copy ,collector_state()->during_concurrent_mark());
>
> I don't need to re-review.
>
> Thanks,
> Erik
>
>> New full webrev:
>> http://cr.openjdk.java.net/~mgerdin/8151711/webrev.1/
>> Incremental webrev:
>> http://cr.openjdk.java.net/~mgerdin/8151711/webrev.0_to_1/
>>
>> Thanks
>> /Mikael
>>
>>> Tom
>>>
>>> On 3/14/2016 4:25 AM, Mikael Gerdin wrote:
>>>> Hi all,
>>>>
>>>> Currently a large part of the G1 collector policy consists of counters
>>>> and number sequences for different measurements performed by the
>>>> collector.
>>>> In order to reduce the overall API surface of the G1CollectorPolicy
>>>> class and possibly allow for different collector policy
>>>> implementations the measurements and simple predictions based on the
>>>> number sequences should be factored out of the policy code. The policy
>>>> will then become more of a decision maker and not a combined data
>>>> store and decision maker.
>>>>
>>>> My current working name for the new class is G1Measurements but I'm
>>>> not overly attached to the name.
>>>>
>>>> I've made the new files "hg copies" of the g1CollectorPolicy files
>>>> since a lot of methods and members are simply moved as-is to the new
>>>> class.
>>>> One thing I did modify was to move decisions based on the
>>>> collector_state() out of the prediction methods and instead based the
>>>> selection on a boolean parameter.
>>>>
>>>> I suggest that in order to review the changes you open up your
>>>> favorite 3-way diff tool and view a 3-way side-by-side diff of
>>>> g1CollectorPolicy.cpp (from my webrev),
>>>> g1CollectorPolicy.cpp (from before my suggested changes),
>>>> g1Measurements.cpp (from my webrev).
>>>>
>>>> In diffuse this would be done as:
>>>> diffuse \
>>>> src/share/vm/gc/g1/g1CollectorPolicy.cpp \
>>>> -r qparent src/share/vm/gc/g1/g1CollectorPolicy.cpp \
>>>> src/share/vm/gc/g1/g1Measurements.cpp
>>>>
>>>> This allows you to (hopefully) verify the moved contents.
>>>> I've tried pretty hard to keep the code in the same order as in the
>>>> original location.
>>>>
>>>> For g1Measurements.hpp I've been a bit more lax to let the header be
>>>> nice and tidy.
>>>>
>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8151711
>>>> Webrev: http://cr.openjdk.java.net/~mgerdin/8151711/webrev.0/
>>>> Testing: RBT gc testing, JPRT, Perf testing on aurora.
>>>>
>>>> Thanks
>>>> /Mikael