RFR: 8256754: Deoptimization::revoke_for_object_deoptimization: stack processing start call is redundant [v2]

[Dean Long]

On Tue, 24 Nov 2020 11:27:10 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

>> This is a XS clean-up of Deoptimization::revoke_for_object_deoptimization() which removes the StackWatermarkSet::start_processing() call.
>> 
>> This is correct because all paths leading to revoke_for_object_deoptimization() are equipped with a KeepStackGCProcessedMark.
>> 
>> Call Tree:
>> 
>> StackWatermarkSet::start_processing(JavaThread *, enum StackWatermarkKind) : void
>>     Deoptimization::revoke_for_object_deoptimization(JavaThread *, frame, RegisterMap *, JavaThread *) : void
>>         Deoptimization::deoptimize_objects_internal(JavaThread *, GrowableArray<compiledVFrame *> *, bool &) : bool
>>             EscapeBarrier::deoptimize_objects_internal(JavaThread *, intptr_t *) : bool
>>                 EscapeBarrier::deoptimize_objects_all_threads() : bool                     // has KeepStackGCProcessedMark
>>                 EscapeBarrier::deoptimize_objects(intptr_t *) : bool
>>                     EscapeBarrier::deoptimize_objects(int, int) : bool                     // has KeepStackGCProcessedMark 
>> 
>> Testing: hotspot_serviceability, jdk_svc, jdk_jdi, vmTestbase_nsk_jdi, vmTestbase_nsk_jvmti, vmTestbase_nsk_jdwp with -XX:+UseZGC.
>
> Richard Reingruber has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Assert stack is kept gc processed.

Marked as reviewed by dlong (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/1381