PING: RFR: JDK-8072913: [REDO] GCCause should distinguish jcmd GC.run from System.gc()

Yasumasa Suenaga yasuenag at gmail.com
Wed May 27 23:52:33 UTC 2015


Hi Jesper,

Thank you for your comment.
I will fix it.


Thanks,

Yasumasa


On 2015/05/28 5:14, Jesper Wilhelmsson wrote:
> Hi,
>
> I like that you removed _jvmti_force_gc from is_user_requested_gc() and used this method throughout. It is cleaner and is_user_requested_gc() makes more sense now.
>
> In vmCMSOperations.cpp I think the comment should say GCCause::_dcmd_gc_run.
>
> Besides that minor comment, looks good!
>
> Thanks,
> /Jesper
>
>
> Yasumasa Suenaga skrev den 20/4/15 15:53:
>> Hi all,
>>
>> I've uploaded webrev for this enhancement.
>> Could you review it?
>>
>> http://cr.openjdk.java.net/~ysuenaga/JDK-8072913/webrev.01/
>>
>>
>> Thanks,
>>
>> Yasumasa
>>
>>
>> On 2015/03/11 22:13, Yasumasa Suenaga wrote:
>>> Hi all,
>>>
>>>> So I think we can remove _jvmti_force_gc from is_user_requested_gc() and add
>>>> _dcmd_gc_run
>>>> to it.
>>>
>>> I've uploaded new webrev, and I've applied it to new patch.
>>> Could you review it?
>>>
>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8072913/webrev.01/
>>>
>>> I also updated jtreg testcase.
>>> It works fine in my environment.
>>>
>>>
>>> Thanks,
>>>
>>> Yasumasa
>>>
>>>
>>> On 2015/02/14 22:10, Yasumasa Suenaga wrote:
>>>> Hi Mikael,
>>>>
>>>>> I'd prefer if you could add a GCCause::is_system_gc_equivalent() which
>>>>> returns true for some set of GCCause enum values, such as
>>>>> _java_lang_system_gc and _dcmd_gc_run
>>>>
>>>> Can I add _dcmd_gc_run to GCCause::is_user_requested_gc() ?
>>>> This function is used with GCCause::is_serviceability_requested_gc() .
>>>> CMSCollector::is_external_interruption() and
>>>> AdaptiveSizePolicy::check_gc_overhead_limit()
>>>>
>>>> is_user_requested_gc() and is_serviceability_requested_gc() checkes
>>>> _jvmti_force_gc
>>>> is selected.
>>>> So I think we can remove _jvmti_force_gc from is_user_requested_gc() and add
>>>> _dcmd_gc_run
>>>> to it.
>>>>
>>>>> A "grep" for _java_lang_system_gc should yield more places where updates may
>>>>> be necessary.
>>>>
>>>> We can use GCCause::is_user_requested_gc() if the proposal in above is accepted.
>>>>
>>>>
>>>> Thanks
>>>>
>>>> Yasumasa
>>>>
>>>>
>>>>
>>>> On 2015/02/13 21:33, Mikael Gerdin wrote:
>>>>> Hi Yasumasa,
>>>>>
>>>>> On 2015-02-11 15:02, Yasumasa Suenaga wrote:
>>>>>> Hi all,
>>>>>>
>>>>>> I've committed JDK-8068589 to add new GCCause - Diagnostic Command.
>>>>>> However, it has been backouted because test is failed [1] and it is not
>>>>>> considered
>>>>>> about concurrent GC: -XX:+ExplicitGCInvokesConcurrent [2].
>>>>>>
>>>>>> I've created patch for this enhancement.
>>>>>> Could you review it?
>>>>>>
>>>>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8072913/webrev.00/
>>>>>
>>>>> I'd prefer if you could add a GCCause::is_system_gc_equivalent() which
>>>>> returns true for some set of GCCause enum values, such as
>>>>> _java_lang_system_gc and _dcmd_gc_run
>>>>>
>>>>> Given that the documentation of the GC.run command is:
>>>>> "GC.run
>>>>> Call java.lang.System.gc().
>>>>>
>>>>> Impact: Medium: Depends on Java heap size and content.
>>>>>
>>>>> Syntax: GC.run"
>>>>>
>>>>> I interpret the documentation that the GC is supposed to be (for all intents
>>>>> and purposes) equivalent to the application invoking System.gc().
>>>>>
>>>>> This would also require updates to other places where we refer to the
>>>>> _java_lang_system_gc GCCause, such as UseAdaptiveSizePolicyWithSystemGC
>>>>>
>>>>> A "grep" for _java_lang_system_gc should yield more places where updates may
>>>>> be necessary.
>>>>>
>>>>> /Mikael
>>>>>
>>>>>>
>>>>>>
>>>>>> I'm jdk9 committer, but I'm not employee at Oracle.
>>>>>> So I need a Sponsor.
>>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Yasumasa
>>>>>>
>>>>>>
>>>>>> [1]
>>>>>> http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2015-February/011957.html
>>>>>>
>>>>>> [2]
>>>>>> http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2015-February/011962.html
>>>>>>
>>>>>>


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