RFR(m): 8221734: Deoptimize with handshakes

Robbin Ehn robbin.ehn at oracle.com
Fri May 3 10:31:25 UTC 2019


Hi, please see this update:

Inc:
http://cr.openjdk.java.net/~rehn/8221734/v2/inc/webrev/index.html
Full:
http://cr.openjdk.java.net/~rehn/8221734/v2/webrev/

# Note
http://cr.openjdk.java.net/~rehn/8221734/v2/inc/webrev/src/hotspot/share/runtime/biasedLocking.cpp.sdiff.html 
line 630
This is revert to the original, I accidental had left in a temporary test 
change, as you can see here in full diff:
http://cr.openjdk.java.net/~rehn/8221734/v2/webrev/src/hotspot/share/runtime/biasedLocking.cpp.sdiff.html

I think I manage to address all review comments.

Dean can you please cast an extra eye on:
http://cr.openjdk.java.net/~rehn/8221734/v2/inc/webrev/src/hotspot/share/oops/method.cpp.sdiff.html
This OR should be correct.

Dan please do the same on the biased locking changes.

I left out the merge with MutexLocker changes, since it was not interesting.
There were some conflicts with JVMCI changes, so incremental contains some parts 
of that merge.

Passes t1-5 and local testing.
I'll continue with some additional testing.

Thanks, Robbin

On 4/25/19 2:05 PM, 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


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