RFR(L): 8226705: [REDO] Deoptimize with handshakes

Robbin Ehn robbin.ehn at oracle.com
Thu Sep 12 11:21:25 UTC 2019

Hi, here is v3, addressing Patricio's and Dan's review comments.



Passed t1-5, doing some more testing also.

Thanks, Robbin

On 8/28/19 11:57 AM, Robbin Ehn wrote:
> Hi, hotspot-dev was the intended list.
> Thanks, Robbin
> On 2019-08-28 09:30, Robbin Ehn wrote:
>> Hi all, please consider,
>> To get away from the issues of us revoking in the handshake, but before deopt
>> the locks get re-biased before we hit deopt handler, we instead revoke in deopt
>> handler.
>> The deopt handler have a JRT_BLOCK/_END which can safepoint so we revoke after
>> that but before we start looking at the monitors, with a NoSafepointVerifier.
>> Here is the previous changeset on top of jdk/jdk tip but due to merge conflicts
>> some pieces did not apply:
>> http://cr.openjdk.java.net/~rehn/8226705/v1/8226705-8221734-baseline/webrev/
>> So this is what was reviewed.
>> The rebase (merge conflict resolutions) and 8224795 bug fix :
>> http://cr.openjdk.java.net/~rehn/8226705/v1/8226705-rebase/webrev/
>> Bug 8224795 fix is here:
>> http://cr.openjdk.java.net/~rehn/8226705/v1/8226705-rebase/webrev/src/hotspot/share/code/nmethod.cpp.sdiff.html 
>> After this we have the same functionally as the reverted change-set.
>> Here is the changes for doing the revoke in deopt handler instead:
>> http://cr.openjdk.java.net/~rehn/8226705/v1/8226705-revoke-on-deopt/webrev/
>> This code was messy adding the deopt revocation in 3 places made it worse.
>> Here is a refactoring of that code. (also removed a dead method in 
>> biasedlocking):
>> http://cr.openjdk.java.net/~rehn/8226705/v1/8226705-refactor/webrev/
>> And here is full:
>> http://cr.openjdk.java.net/~rehn/8226705/v1/full/webrev/
>> Also a full squashed patch file:
>> http://cr.openjdk.java.net/~rehn/8226705/v1/full/full.patch
>> Latest test run I did t1-t6, Linux/Windows x64 have passed, MacOSX still
>> running.
>> Thanks, Robbin

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