RFR (XS): 8200362: G1Mux2Closure should disable implicit oop verification (original) (raw)

Stefan Johansson stefan.johansson at oracle.com
Thu Mar 29 07:52:03 UTC 2018

Hi Thomas,

On 2018-03-28 17:27, Thomas Schatzl wrote:

Hi all,

can I have reviews for this small change that fixes some annoyance when debugging with G1? In particular, G1Mux2Closure is used by verification to verify and in case of error print out g1 specific error messages. However, since G1Mux2Closure is an OopClosure, it is actually wrapped by NoHeaderExtendedOopClosure in oopiterate* calls. ExtendedOopClosure has its own verification that is very generic, and may trigger in the same situations as G1Mux2Closure. Disable this implicit verification for G1Mux2Closure so that we always get the g1 specific error messages. CR: https://bugs.openjdk.java.net/browse/JDK-8200362 Webrev: http://cr.openjdk.java.net/~tschatzl/8200362/webrev/ Nice change, always good to get detailed information. I think you need to change the code using the G1Mux2Closure as well. On line 666 in heapRegion.cpp:   G1Mux2Closure mux(&vl_cl, &vr_cl);   obj->oop_iterate_no_header(&mux); This should now be a normal oop_iterate(&mux) to make sure the right verification is done.

Thanks, Stefan

Testing: (mostly finished) hs-tier 1+2

Thanks, Thomas

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