RFR(m): 8221734: Deoptimize with handshakes

[Patricio Chilano]

Hi Robbin,

Changes to biased locking look good! Thanks for the change.

nit:
--- a/src/hotspot/share/runtime/deoptimization.cpp
+++ b/src/hotspot/share/runtime/deoptimization.cpp
@@ -1318,3 +1318,2 @@
      oop obj = (objects_to_revoke->at(i))();
-   markOop mark = obj->mark();
BiasedLocking::revoke_own_locks_in_handshake(objects_to_revoke->at(i), 
thread);


Thanks!

Patricio

On 5/20/19 5:04 AM, Robbin Ehn wrote:
> Hi all, please see this update v4.
>
> I have fixed the simplification Patricio talked about and David's nit.
>
> The interesting part is now the full diff of bias locking cpp file:
> http://cr.openjdk.java.net/~rehn/8221734/v4/webrev/src/hotspot/share/runtime/biasedLocking.cpp.sdiff.html 
>
> It's very clean.
>
> Full:
> http://cr.openjdk.java.net/~rehn/8221734/v4/
> Inc:
> http://cr.openjdk.java.net/~rehn/8221734/v4/inc/
>
> I have seen no issues in T1-7, KS and other assorted testing.
>
> Thanks, Robbin
>
>
> On 2019-04-25 14:05, Robbin Ehn wrote:
>> Hi all, please review.
>>
>> Let's deopt with handshakes.
>> Removed VM op Deoptimize, instead we handshake.
>> Locks needs to be inflate since we are not in a safepoint.
>>
>> Goes on top of:
>> https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2019-April/033491.html 
>>
>>
>> Code:
>> http://cr.openjdk.java.net/~rehn/8221734/v1/webrev/index.html
>> Issue:
>> https://bugs.openjdk.java.net/browse/JDK-8221734
>>
>> Passes t1-7 and multiple t1-5 runs.
>>
>> A few startup benchmark see a small speedup.
>>
>> Thanks, Robbin