RFR: 8140348: Convert TraceSafepoint to Unified Logging

[David Holmes]

On 3/11/2015 1:39 AM, Coleen Phillimore wrote:
>
>
> On 11/1/15 8:57 PM, David Holmes wrote:
>> On 24/10/2015 7:58 AM, Coleen Phillimore wrote:
>>>
>>> Copying Mattis,  Mattis, this is the second flag to be converted to use
>>> the Unified Logging framework.
>>>
>>> -XX:+TraceSafepoint was a develop mode flag but Unified Logging makes it
>>> available in product mode.  This may be useful to customers. Your
>>> comments are appreciated, as well as comments from the openjdk
>>> community.
>>
>> I'm concerned that a number of previously Develop-only trace flags are
>> now being made product flags with the conversion to Unified-logging!
>> Has anyone done the performance checks for that? Individually they may
>> seem okay but what about in combination?
>>
>> There has to be a balance between the perceived utility of a flag and
>> the cost everyone has to pay whether they turn the flag on or not.
>
> See the review thread for RFR: 8139564: Convert TraceDefaultMethods to
> Unified Logging
>
> http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2015-October/016059.html
>
>
> Yes, we discussed this and decided to make all flags product pending any
> problems discovered at a later time in the jdk9 release cycle.    Rachel
> is doing performance testing on each flag individually as converted, but
> we could do a run at the end of the first set to be migrated, and see if
> there are problems then.

I'm concerned about the cumulative effects. I'm also concerned that even 
for non-product flags the logging will now have overheads in the product 
builds.

David

> Thanks,
> Coleen
>
>>
>> Thanks,
>> David
>>
>>> Thanks,
>>> Coleen
>>>
>>>
>>> On 10/23/15 3:59 PM, Rachel Protacio wrote:
>>>> Thank you, Harold! I'll fix that.
>>>> Rachel
>>>>
>>>> On 10/23/2015 9:09 AM, harold seigel wrote:
>>>>> Hi Rachel,
>>>>>
>>>>> The change s look good.
>>>>>
>>>>> One nit, if SafepointTest.java is a new file then you can remove
>>>>> "2014,  " for its copyright.
>>>>>
>>>>> Thanks, Harold
>>>>>
>>>>> On 10/22/2015 1:33 PM, Rachel Protacio wrote:
>>>>>> Hello,
>>>>>>
>>>>>> Please review my next logging enhancement.
>>>>>>
>>>>>> Summary: The former -XX:+TraceSafepoint flag is updated to the
>>>>>> unified logging framework and is now replaced with -Xlog:safepoint
>>>>>> in product mode.
>>>>>>
>>>>>> open webrev: http://cr.openjdk.java.net/~rprotacio/8140348/
>>>>>> bug link: https://bugs.openjdk.java.net/browse/JDK-8140348
>>>>>> testing: Passes JPRT, RBT, and RefWorkload performance testing.
>>>>>>
>>>>>> A compatibility request has been accepted with regard to this change.
>>>>>>
>>>>>> Thank you,
>>>>>> Rachel
>>>>>
>>>>
>>>
>