RFR (M) 8198720: Obsolete PrintSafepointStatistics, PrintSafepointStatisticsTimeout and PrintSafepointStatisticsCount options

[coleen.phillimore at oracle.com]

I've kept the output the same and converted to UL.  To get the lines not 
to shift due to uptime printing, you can use the option:

-Xlog:safepoint+stats=debug:<outputfile>:tags or none instead of tags.

I could alias PrintSafepointStatistics to this: 
-Xlog:safepoint+stats=debug::none as this option gets verbose. Having 
the ability to send the output to a gc.log file is pretty nice though so 
worth using all the logging options.

Please review:

open webrev at http://cr.openjdk.java.net/~coleenp/8198720.02/webrev

Tested with tier1-3.

Thanks,
Coleen

On 7/9/18 11:26 PM, coleen.phillimore at oracle.com wrote:
>
> Hi Aleksey,
>
> I rewrote the logging to use UL and to keep the old format:  see 
> http://cr.openjdk.java.net/~coleenp/gc.log
> It does shift when the time in the logging adds another digit.  I 
> don't know how to fix that.   Does this look ok otherwise?
>
> thanks,
> Coleen
>
>
> On 7/9/18 5:42 PM, coleen.phillimore at oracle.com wrote:
>>
>>
>> On 7/9/18 4:08 PM, Aleksey Shipilev wrote:
>>> Thank you!
>>>
>>> Most latency-savvy folks "out there" run with some sort of 
>>> safepointing profiling, which in many
>>> cases include PrintSafepointStatistics tables.
>>
>> That was the original reason I was looking at this logging.  I think 
>> the trouble with the times is that they are ms and mostly zero.  I 
>> wonder if MILLIUNITS would be better for these times:
>>
>>              (int64_t)(sstats->_time_to_spin / MICROUNITS),
>>              (int64_t)(sstats->_time_to_wait_to_block / MICROUNITS),
>>              (int64_t)(sstats->_time_to_sync / MICROUNITS),
>>              (int64_t)(sstats->_time_to_do_cleanups / MICROUNITS),
>>              (int64_t)(sstats->_time_to_exec_vmop / MICROUNITS));   
>> <= this has nonzero values for GC pauses
>>
>> What do you think?
>>
>> thanks,
>> Coleen
>>>
>>> -Aleksey
>>>
>>> On 07/09/2018 08:35 PM, coleen.phillimore at oracle.com wrote:
>>>> Okay, somehow the columns of numbers didn't look very useful on my 
>>>> screen to me, and I wanted to
>>>> convert this to UL (and straighten out the logic), so that's why I 
>>>> made this change.   I asked
>>>> around internally to see which people would care about the format 
>>>> change and didn't find anyone
>>>> specific.  Now I know!
>>>>
>>>> Let me rework this to use UL but keep the table.
>>>>
>>>> I'll withdraw this change for now.
>>>>
>>>> Thank you for the quick feedback.
>>>> Coleen
>>>>
>>>> On 7/9/18 1:58 PM, Aleksey Shipilev wrote:
>>>>> On 07/09/2018 07:48 PM, coleen.phillimore at oracle.com wrote:
>>>>>> Summary: Convert PrintSafepointStatistics to UL
>>>>>>
>>>>>> open webrev at http://cr.openjdk.java.net/~coleenp/8198720.01/webrev
>>>>>> bug link https://bugs.openjdk.java.net/browse/JDK-8198720
>>>>> The synopsis is misleading: it is not only obsoleting 
>>>>> PrintSafepoint* options, it also reformats the
>>>>> output!
>>>>>
>>>>> We did JDK-8180482 not that long ago, and the reason was that both 
>>>>> people and machine tools are
>>>>> accustomed to the particular non-noisy format for that table. I am 
>>>>> not at all convinced that
>>>>> proposed format [2] is better than current version [3]. Can we 
>>>>> keep (at least some resemblance of)
>>>>> the old format, please?
>>>>>
>>>>> -Aleksey
>>>>>
>>>>> [1] https://bugs.openjdk.java.net/browse/JDK-8180482
>>>>> [2] 
>>>>> https://bugs.openjdk.java.net/secure/attachment/75330/out.safepoint-logging
>>>>> [3] http://cr.openjdk.java.net/~shade/8180482/after.txt
>>>>>
>>>
>>
>