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

[serguei.spitsyn at oracle.com]

On 4/27/15 1:05 PM, serguei.spitsyn at oracle.com wrote:
> 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.

Sorry, I forgot to tell that my plan is to open another bug that should
cover moving all this adjustments to the end of redefinition.
This was a source of the confusion!

Thanks,
Serguei

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