RFR (S) 8073705: more performance issues in class redefinition

[serguei.spitsyn at oracle.com]

Hi Coleen,

Thank you for the review!

On 4/27/15 10:49 AM, Coleen Phillimore wrote:
>
> Serguei,
>
> This looks nice.  I thought this change was going to delay calling 
> AdjustCpoolCacheAndVtable until the end of the redefinition, rather 
> than for each class, so was a bit confused by the change.

I consider this for as a next round of optimizations which is more risky.
We need to decide when we are Ok to take this risk.
My guess is that it is better to do it together with the constant pool 
merge elimination.

>
> Your change is a nice cleanup and improves MethodHandle method 
> replacement performance.

Thanks!

>
> Your backport may not be simple for jdk8 because PreviousVersionNode 
> is another type and not an InstanceKlass. Maybe you've convinced me 
> that it's worth backporting those changes too.  Let me know.

I've already backported the first chunk where this problem was hit.
It seems, this one should not be harder to backport.

Thanks!
Serguei

>
> Thanks,
> Coleen
>
> On 4/10/15, 4:29 PM, serguei.spitsyn at oracle.com wrote:
>> Hi Coleen and Dan,
>>
>> This is the second class redefinition scalability/optimization fix 
>> that is in my queue to push into 9 and 8u60.
>>
>> The approach is similar to the first one but much smaller.
>> For convenience, these are the links to the first scalability fix:
>>      Bug report: https://bugs.openjdk.java.net/browse/JDK-8073705
>>      Open webrev: 
>> http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/hotspot/8046246-JVMTI-redefscale.2/
>>
>> Please, let me know if you have any chance to review this.
>> This is the last one that is waiting for your attention! :)
>>
>> Thanks,
>> Serguei
>>
>> On 3/26/15 7:38 PM, serguei.spitsyn at oracle.com wrote:
>>> Please, review the fix for:
>>>   https://bugs.openjdk.java.net/browse/JDK-8073705
>>>
>>>
>>> Open hotspot webrev:
>>> http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/hotspot/8073705-JVMTI-redefscale2.1/ 
>>>
>>>
>>>
>>> Summary:
>>>
>>>    This is the 2-nd round of performance/calability fixes in class 
>>> redefinition.
>>>    This time, the two remaining issues that were left alone in the 
>>> first round fix:
>>>      - optimized ConstantPoolCache::adjust_method_entries() is used 
>>> for previous versions
>>>      - the MemberNameTable::adjust_method_entries() has been 
>>> optimized too
>>>      - some cleanup
>>>
>>>
>>> Testing:
>>>   In progress: nsk redefine classes tests, JTREG 
>>> java/lang/instrument, com/sun/jdi
>>>
>>>
>>> Thanks,
>>> Serguei
>>>
>>
>