RFR: 8318015: Lock inflation not needed for OSR or Deopt for new locking modes [v2]

[Martin Doerr]

On Fri, 13 Oct 2023 14:17:45 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Skip copying displaced header.
>
> src/hotspot/share/runtime/basicLock.cpp line 70:
> 
>> 68: 
>> 69:   if (LockingMode == LM_LEGACY && displaced_header().is_neutral()) {
>> 70:     // The object is locked and the resulting ObjectMonitor* will also be
> 
> Isn't the set_displaced_header() below also unnecessary for other locking modes, i.e shouldn't it be `if (LockingMode != LM_LEGACY) { return; }`?

Correct. We can skip copying the displaced header completely (also for OSR). I've updated the PR.

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PR Review Comment: https://git.openjdk.org/jdk/pull/16165#discussion_r1358361190