Aleksey Shipilëv

Sorry, it slipped off my radar. /open

The overwhemling majority of users consume JMH through Maven Central releases. So, unless you are planning to publish SNAPSHOT versions somewhere, I see no particular value in building JMH separately...

Hold on. Here is the C2 SATB barrier check, which checks gc-state for `MARKING`: https://github.com/openjdk/jdk/blob/2f10a316ff0c5a4c124b94f6fabb38fb119d2c82/src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp#L241-L243 What this PR changes is `ShenandoahBarrierSetAssembler::satb_write_barrier_impl`, which is the SATB barrier for generic assembly code....

There is currently a regression in the original code, [JDK-8332670](https://bugs.openjdk.org/browse/JDK-8332670), which may explain some instability on PPC.

@fisk @stefank -- are you good with this for ZGC?

> Having said that, perhaps we should file a separate issue to remove that check, since it seems to fix an actual bug, while I guess this was meant more...

/sponsor

> This looks ready to me. I think we need jcstress with C1 and C2, and we should be done. @shipilev , do you agree? Yes. Just run jcstress with...

Note that current jcstress run would likely fail due to [JDK-8332670](https://bugs.openjdk.org/browse/JDK-8332670).

> I can run the jcstress test. I will run fastdebug build with `java -jar jcstress-latest.jar -tb 24h` Is it the correct command ? Yes, I think so.