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

[Lois Foltan]

On 7/11/2018 9:15 AM, coleen.phillimore at oracle.com wrote:
>
> 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

Hi Coleen,
This looks good.  One minor comment:

share/runtime/safepoint.hpp line #111 - can you clarify why the "#if 
0/#endif code shouldn't just be removed?

Thanks,
Lois

>
> 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
>>>>>>
>>>>
>>>
>>
>