RFR(8u): JDK-8145442: Add the facility to verify remembered sets for G1

Poonam Bajaj Parhar poonam.bajaj at oracle.com
Thu Jan 28 22:56:15 UTC 2016


Hello,

On 1/28/2016 2:39 PM, Jon Masamitsu wrote:
>
>
> On 01/28/2016 02:32 PM, Poonam Bajaj Parhar wrote:
>> Hello Jon,
>>
>> On 1/28/2016 1:08 PM, Jon Masamitsu wrote:
>>>
>>>
>>> On 01/28/2016 12:37 PM, Poonam Bajaj Parhar wrote:
>>>> Hello Jon,
>>>>
>>>> On 1/28/2016 11:48 AM, Jon Masamitsu wrote:
>>>>> Poonam,
>>>>>
>>>>> Changes look good.
>>>>
>>>> Thanks for the review.
>>>>
>>>>>
>>>>> With VerifyBeforeGC and VerifyAfterGC the gc logs will look
>>>>> a little different?  The rem-set verify part of the log will be 
>>>>> separate?
>>>>> Instead of
>>>>>
>>>>> 2.701: [Full GC (Allocation Failure) VerifyBeforeGC:[Verifying 
>>>>> threads heap Roots HeapRegionSets HeapRegions RemSet syms strs 
>>>>> zone dict cldg metaspace chunks hand C-heap code cache ]
>>>>>
>>>>> the rem-set message will be from
>>>>>
>>>>> 4028       if (VerifyRememberedSets) {
>>>>> 4029         if (PrintGCDetails) {
>>>>> 4030           gclog_or_tty->print_cr("[Verifying RemSets before GC]");
>>>>> 4031         }
>>>
>>> Should  this code above consider the VerifySilently flag?
>>
>> Yes, it can. But I am afraid since this is a backport of the fix that 
>> has been integrated into jdk9 it would have to be done as a separate 
>> change.
>
> Since the reason to add the VerifySilently is that it exits in jdk8 
> and not in jdk9,

Oh yes, Unified GC logging removed it in 9.

> I think you can integrate it in the same patch.   If you're not 
> comfortable with
> that, it's fine to add the change separately.

I will add the check for VerifySilently in this patch itself.

Thanks,
Poonam

>
> Jon
>
>>
>> Thanks,
>> Poonam
>>
>>>
>>> Jon
>>>>
>>>> Yes, the output with VerifyRememberedSets will be different from 
>>>> the output with VerifyBeforeGC and VerifyAfterGC flags. Since 
>>>> VerifyRememberedSets is not dependent on VerifyBeforeGC and 
>>>> VerifyAfterGC options, it will be used independently when we don't 
>>>> want to verify everything.
>>>>
>>>> Thanks,
>>>> Poonam
>>>>
>>>>>
>>>>> Jon
>>>>>
>>>>>
>>>>> On 01/27/2016 12:03 PM, Poonam Bajaj Parhar wrote:
>>>>>> Hello,
>>>>>>
>>>>>> Could I get reviews for the backport of the fix for JDK-8145442 
>>>>>> <https://bugs.openjdk.java.net/browse/JDK-8145442> to jdk8u.
>>>>>>
>>>>>> Webrev: http://cr.openjdk.java.net/~poonam/8145442/webrev.8u/
>>>>>> jdk9 changeset: 
>>>>>> http://hg.openjdk.java.net/jdk9/hs-rt/hotspot/rev/3666a5638df2
>>>>>> Testing: JPRT, GCBasher
>>>>>>
>>>>>> Thanks,
>>>>>> Poonam
>>>>>>
>>>>>
>>>>
>>>
>>
>

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