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

[dean.long at oracle.com]

Hi Robbin.

I like the new CompiledMethod_lock.  I had some concerns with 8224674 
about races between make_not_entrant and make_unloaded, so I was half 
expecting CompiledMethod_lock to be used at a higher level than 
Patching_lock and protect the whole call to make_not_entrant and 
make_unloaded.  Does make_unloaded need to use CompiledMethod_lock at all?

dl

PS - Erik said he would file a RFE to refactor/cleanup make_not_entrant 
and make_unloaded, but I can't find it.

On 9/12/19 4:21 AM, Robbin Ehn wrote:
> Hi, here is v3, addressing Patricio's and Dan's review comments.
>
> Inc:
> http://cr.openjdk.java.net/~rehn/8226705/v3/inc/webrev/
>
> Full:
> http://cr.openjdk.java.net/~rehn/8226705/v3/full/webrev/
>
> 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
>>>
>>>