RFR(S): 8209544: AES encrypt performance regression in jdk11b11

[Dmitry Chuyko]

On 09/05/2018 07:00 PM, Vladimir Kozlov wrote:
> Hi Dmitry,
>
> What are (* bytes) values? Is it bytecode size? Why it is different?
It is a distance between captured event addresses in particular hot 
region (first and last).
Perf attributes one more instruction (2 instrs down) in 132 bytes case, 
it is just a comparison with 52 (0.37%). The code is the same so this 
doesn't look too suspicious to me. But different percentage for stub 
parts does. Note, regions percentage distribution after inlining looks 
the same, e.g.

....[Hottest Methods (after 
inlining)]..............................................................
  83.67%        runtime stub  StubRoutines::aescrypt_encryptBlock
   7.69%         c2, level 4 
com.sun.crypto.provider.CipherCore::doFinal, version 868
   4.34%         c2, level 4 
org.openjdk.bench.javax.crypto.small.generated.AESBench_encrypt_jmhTest::encrypt_thrpt_jmhStub, 
version 889

and

  84.03%        runtime stub  StubRoutines::aescrypt_encryptBlock
   7.85%         c2, level 4 
com.sun.crypto.provider.CipherCore::doFinal, version 860
   4.22%         c2, level 4 
org.openjdk.bench.javax.crypto.small.generated.AESBench_encrypt_jmhTest::encrypt_thrpt_jmhStub, 
version 880

-Dmitry

>
> Thanks,
> Vladimir
>
> On 9/5/18 8:50 AM, Dmitry Chuyko wrote:
>> I made few runs on ThunderX2 (aarch64). It is funny but I see almost 
>> reverse difference in small.AESBench.encrypt: ~4% regression for both 
>> -XX:-UseSwitchProfiling and patched version against current code. No 
>> difference for full.AESBench.encrypt.
>>
>> Stub code is the same and profiles differ slightly:
>>
>> Mainline
>>   53.91%        runtime stub StubRoutines::aescrypt_encryptBlock (128 
>> bytes)
>>   29.76%        runtime stub StubRoutines::aescrypt_encryptBlock (40 
>> bytes)
>>    7.64%         c2, level 4 
>> com.sun.crypto.provider.CipherCore::doFinal, version 868 (356 bytes)
>>
>> -XX:+UnlockExperimentalVMOptions -XX:-UseSwitchProfiling
>>   57.08%        runtime stub StubRoutines::aescrypt_encryptBlock (132 
>> bytes)
>>   26.95%        runtime stub StubRoutines::aescrypt_encryptBlock (40 
>> bytes)
>>    7.85%         c2, level 4 
>> com.sun.crypto.provider.CipherCore::doFinal, version 860 (384 bytes)
>>
>> Patched
>>   58.15%        runtime stub StubRoutines::aescrypt_encryptBlock (132 
>> bytes)
>>   26.44%        runtime stub StubRoutines::aescrypt_encryptBlock (40 
>> bytes)
>>    6.67%         c2, level 4 
>> com.sun.crypto.provider.CipherCore::doFinal, version 866 (128 bytes)
>>
>> -Dmitry
>>
>> On 09/05/2018 11:05 AM, Roland Westrelin wrote:
>>> Thanks for the review. Anyone else?
>>>
>>> Roland.
>>