RFR(S): 8228649: [PPC64] SA reads wrong slots from interpreter frames

[Lindenmaier, Goetz]

Hi Martin,

I had a look at your change. 

Thanks for explaining that you had to remove the extra
slot in the debug build so that the stack looks the same 
in both builds offline.
It probably could be distinguished in the build of SA, too, 
but this way it's probably more stable.  Also, I don't 
remember we ever ran into this stack guard.
You might want to describe in the bug how you have fixed this.

Did you check that all the StackOverflow tests still work in the 
debug build?  Like those that depend that a certain frame
causes the overflow?  With smaller frames, this might affect 
the tests.

In the ProblemList, please remove the bugids of 8211767.

@Gustavo, I don't think closing 8211767 is a good idea. It is 
still used for a row of excluded SA tests in the ProblemList, 
see also the comment further down in the bug. 

Best regards,
  Goetz.

> -----Original Message-----
> From: Doerr, Martin
> Sent: Freitag, 26. Juli 2019 13:02
> To: serviceability-dev at openjdk.java.net; hotspot-runtime-
> dev at openjdk.java.net; Lindenmaier, Goetz <goetz.lindenmaier at sap.com>;
> Gustavo Romero <gromero at linux.vnet.ibm.com>
> Subject: RFR(S): 8228649: [PPC64] SA reads wrong slots from interpreter
> frames
> 
> Hi,
> 
> 
> 
> the jtreg test "serviceability/sa/sadebugd/DebugdConnectTest.java" fails with
> "AssertionFailure: result must >= than stack pointer" on PPC64.
> 
> The Java code doesn't read the right slots for the interpreter frame's monitors.
> 
> 
> 
> I've removed the extra "reserved" slot which existed only in debug builds. It
> was used as additional frame check, but I think we can live without it.
> 
> My new proposal also initializes all relevant interpreter frame slots for better
> tool support:
> 
> http://cr.openjdk.java.net/~mdoerr/8228649_PPC64_sa/webrev.00/
> 
> 
> 
> Please review.
> 
> 
> 
> Best regards,
> 
> Martin
> 
>