RFR: 8253910: UseCompressedClassPointers depends on UseCompressedOops in vmError.cpp

[Richard Reingruber]

On Thu, 7 Jan 2021 13:54:25 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> As noted in the bug report, there are places in `vmError.cpp`, where information on compressed classes is only printed if compressed oops are enabled. After JDK-8241825 both features should be independent. In addition to 2 reported places, we also need to print the setting in JVM modeline.
> 
> Sample outputs:
> 
> Command Line: Crash
> ...
> # Java VM: OpenJDK 64-Bit Server VM (fastdebug 17-internal+0-adhoc.shade.jdk, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
> ...
> VM Mutex/Monitor currently owned by a thread: None
> 
> Heap address: 0x0000000082000000, size: 30688 MB, Compressed Oops mode: Zero based, Oop shift amount: 3
> 
> CDS archive(s) mapped at: [0x0000000800000000-0x0000000800c5c000-0x0000000800c5c000), size 12959744, SharedBaseAddress: 0x0000000800000000, ArchiveRelocationMode: 0.
> Compressed class space mapped at: 0x0000000801000000-0x0000000841000000, reserved size: 1073741824
> Narrow klass base: 0x0000000800000000, Narrow klass shift: 3, Narrow klass range: 0x100000000
> 
> GC Precious Log:
> 
> Command Line: -XX:-UseCompressedOops Crash
> ...
> # Java VM: OpenJDK 64-Bit Server VM (fastdebug 17-internal+0-adhoc.shade.jdk, mixed mode, sharing, tiered, compressed class ptrs, g1 gc, linux-amd64)
> ...
> VM Mutex/Monitor currently owned by a thread: None
> 
> CDS archive(s) mapped at: [0x0000000800000000-0x0000000800c2f000-0x0000000800c2f000), size 12775424, SharedBaseAddress: 0x0000000800000000, ArchiveRelocationMode: 0.
> Compressed class space mapped at: 0x0000000801000000-0x0000000841000000, reserved size: 1073741824
> Narrow klass base: 0x0000000800000000, Narrow klass shift: 3, Narrow klass range: 0x100000000
> 
> GC Precious Log:
> ...
> 
> Command Line: -XX:-UseCompressedOops -XX:-UseCompressedClassPointers Crash
> ...
> # Java VM: OpenJDK 64-Bit Server VM (fastdebug 17-internal+0-adhoc.shade.jdk, mixed mode, tiered, g1 gc, linux-amd64)
> ...
> VM Mutex/Monitor currently owned by a thread: None
> 
> GC Precious Log:
> ...

The change looks good to me. Thanks for fixing.

-------------

Marked as reviewed by rrich (Committer).

PR: https://git.openjdk.java.net/jdk/pull/1974